U.S. patent application number 13/321173 was filed with the patent office on 2012-04-26 for chlorobenzene derivative, optically isotropic liquid crystal medium, and optical device.
This patent application is currently assigned to JNC PETROCHEMICAL CORPORATION. Invention is credited to Yasuhiro Haseba, Takafumi Kuninobu.
Application Number | 20120099039 13/321173 |
Document ID | / |
Family ID | 43126114 |
Filed Date | 2012-04-26 |
United States Patent
Application |
20120099039 |
Kind Code |
A1 |
Haseba; Yasuhiro ; et
al. |
April 26, 2012 |
CHLOROBENZENE DERIVATIVE, OPTICALLY ISOTROPIC LIQUID CRYSTAL
MEDIUM, AND OPTICAL DEVICE
Abstract
A liquid crystal compound having a large refractive index
anisotropy, a large dielectric anisotropy, and a low melting point,
and a liquid crystal medium having a liquid crystal phase over a
wide temperature range, a large refractive index anisotropy, a
large dielectric anisotropy, and having an optically isotropic
liquid crystal phase, are provided. The present invention is a
liquid crystal compound having a chlorobenzene ring, and a liquid
crystal medium characterized by containing the liquid crystal
compound and a chiral reagent, and exhibiting an optically
isotropic liquid crystal phase.
Inventors: |
Haseba; Yasuhiro; (Chiba,
JP) ; Kuninobu; Takafumi; (Chiba, JP) |
Assignee: |
JNC PETROCHEMICAL
CORPORATION
TOKYO
JP
JNC CORPORATION
TOKYO
JP
|
Family ID: |
43126114 |
Appl. No.: |
13/321173 |
Filed: |
May 7, 2010 |
PCT Filed: |
May 7, 2010 |
PCT NO: |
PCT/JP2010/057800 |
371 Date: |
December 22, 2011 |
Current U.S.
Class: |
349/33 ;
252/299.5; 252/299.61; 252/299.63; 252/299.66; 549/374; 560/73;
568/642 |
Current CPC
Class: |
C09K 19/20 20130101;
C09K 2019/0411 20130101; C09K 19/588 20130101; C09K 2323/00
20200801; C09K 2019/0466 20130101; Y10T 428/10 20150115 |
Class at
Publication: |
349/33 ;
252/299.66; 252/299.63; 252/299.61; 252/299.5; 568/642; 549/374;
560/73 |
International
Class: |
G02F 1/133 20060101
G02F001/133; C09K 19/30 20060101 C09K019/30; C07C 69/76 20060101
C07C069/76; C09K 19/54 20060101 C09K019/54; C07C 43/225 20060101
C07C043/225; C07D 319/06 20060101 C07D319/06; C09K 19/12 20060101
C09K019/12; C09K 19/34 20060101 C09K019/34 |
Foreign Application Data
Date |
Code |
Application Number |
May 19, 2009 |
JP |
2009-120439 |
Claims
1. A compound, represented by Formula (1): ##STR00121## wherein in
Formula (1), R.sup.1 is hydrogen or a C.sub.1-20 alkyl, wherein
arbitrary --CH.sub.2-- in the alkyl may be substituted with --O--,
--S--, --COO--, --COO--, --CH.dbd.CH--, --CF.dbd.CF-- or
--C.dbd.C--, and arbitrary hydrogen in the alkyl and the alkyl with
arbitrary --CH.sub.2-- substituted with --O--, --S--, --COO--,
--COO--, --CH.dbd.CH--, --CF.dbd.CF--, or --C.ident.C-- may be
substituted with halogen or a C.sub.1-3 alkyl; Z.sup.1, Z.sup.2,
Z.sup.3, Z.sup.4, Z.sup.5, and Z.sup.6 are independently a single
bond or --CF.sub.2O--, provided that at least one of Z.sup.1,
Z.sup.2, Z.sup.3, Z.sup.4, Z.sup.5, and Z.sup.6 is --CF.sub.2O--;
L.sup.1, L.sup.2, L.sup.3, L.sup.4, and L.sup.5 are independently
hydrogen or fluorine; X.sup.1 is halogen, --C.ident.N,
--N.dbd.C.dbd.S, --SF.sub.5 or a C.sub.1-3 alkyl in which arbitrary
hydrogen is substituted with fluorine, and arbitrary --CH.sub.2--
in the alkyl may be substituted with --O--, --S--, --CH.dbd.CH-- or
--C.ident.C--; and l, m, n, o and p are independently 0 or 1, and
1.ltoreq.1 +m+n+o+p.ltoreq.2.
2. The liquid crystal compound according to claim 1, wherein in
Formula (1), R.sup.1 is a C.sub.1-20 alkyl, a C.sub.2-21 alkenyl, a
C.sub.2-21 alkynyl, a C.sub.1-19 alkoxy, a C.sub.2-20 alkenyloxy, a
C.sub.1-19 alkylthio, a C.sub.2-19 alkenylthio, or
--(CH.sub.2).sub.v--CH.dbd.CF.sub.2, in which v is 0 or an integer
of 1-19; and X.sup.1 is halogen, --SF.sub.5, --CH.sub.2F,
--CHF.sub.2, --CF.sub.3, --(CH.sub.2).sub.2--F,
--CF.sub.2CH.sub.2F, --CF.sub.2CHF.sub.2, --CH.sub.2CF.sub.3,
--CF.sub.2CF.sub.3, --(CH.sub.2).sub.3--F, --(CF.sub.2).sub.3--F,
--CF.sub.2CHFCF.sub.3, --CHFCF.sub.2CF.sub.3,
--(CH.sub.2).sub.4--F, --(CF.sub.2).sub.4--F,
--(CH.sub.2).sub.5--F, --(CF.sub.2).sub.5--F, --OCH.sub.2F,
--OCHF.sub.2, --OCF.sub.3, --O--(CH.sub.2).sub.2--F,
--OCF.sub.2CH.sub.2F, --OCF.sub.2CHF.sub.2, --OCH.sub.2CF.sub.3,
--O--(CH.sub.2).sub.3--F, --O--(CF.sub.2).sub.3--F,
--OCF.sub.2CHFCF.sub.3, --OCHFCF.sub.2CF.sub.3,
--O(CH.sub.2).sub.4--F, --O--(CF.sub.2).sub.4--F,
--O--(CH.sub.2).sub.5--F, --O--(CF.sub.2).sub.5--F, --CH.dbd.CHF,
--CH.dbd.CF.sub.2, --CF.dbd.CHF, --CH.dbd.CHCH.sub.2F,
--CH.dbd.CHCF.sub.3, --(CH.sub.2).sub.2--CH.dbd.CF.sub.2,
--CH.sub.2CH.dbd.CHCF.sub.3, or --CH.dbd.CHCF.sub.2CF.sub.3.
3. The liquid crystal compound according to claim 1, wherein in
Formula (1), R.sup.1 is a C.sub.1-20 alkyl or a C.sub.2-21
alkenyl.
4. The liquid crystal compound according to claim 1, represented by
Formula (1-1), Formula (1-2), Formula (1-3), Formula (1-4), Formula
(1-5) or Formula (1-6): ##STR00122## wherein in the formulas,
R.sup.1 is a C.sub.1-20 alkyl, a C.sub.2-21 alkenyl, a C.sub.2-21
alkynyl, a C.sub.1-19 alkoxy, a C.sub.2-20 alkenyloxy, a C.sub.1-10
alkylthio, a C.sub.2-19 alkenylthio, or
--(CH.sub.2).sub.v--CH.dbd.CF.sub.2, in which v is 0 or an integer
of 1-19; Z.sup.1, Z.sup.2, Z.sup.3, Z.sup.4, Z.sup.5 and Z.sup.6
are independently a single bond or --CF.sub.2O--, provided that at
least one of Z.sup.1, Z.sup.2, Z.sup.3, Z.sup.4, L, Z.sup.5 and
Z.sup.6 is --CF.sub.2O--; L.sup.1, L.sup.2, L.sup.3, L.sup.4 and
L.sup.5 are independently hydrogen or fluorine; and X.sup.1 is
halogen, --SF.sub.5, --CH.sub.2F, --CHF.sub.2, --CF.sub.3,
--(CH.sub.2).sub.2--F, --CF.sub.2CH.sub.2F, --CF.sub.2CHF.sub.2,
--CH.sub.2CF.sub.3, --CF.sub.2CF.sub.3, --(CH.sub.2).sub.3--F,
--(CF.sub.2).sub.3--F, --CF.sub.2CHFCF.sub.3,
--CHFCF.sub.2CF.sub.3, --(CH.sub.2).sub.4--F,
--(CF.sub.2).sub.4--F, --(CH.sub.2).sub.5--F,
--(CF.sub.2).sub.5--F, --OCH.sub.2F, --OCHF.sub.2, --OCF.sub.3,
--O--(CH.sub.2).sub.2--F, --OCF.sub.2CH.sub.2F,
--OCF.sub.2CHF.sub.2, --OCH.sub.2CF.sub.3,
--O--(CH.sub.2).sub.3--F, --O--(CF.sub.2).sub.3--F,
--OCF.sub.2CHFCF.sub.3, --OCHFCF.sub.2CF.sub.3,
--O(CH.sub.2).sub.4--F, --O--(CF.sub.2).sub.4--F,
--O--(CH.sub.2).sub.5--F, --O--(CF.sub.2).sub.5--F, --CH.dbd.CHF,
--CH.dbd.CF.sub.2, --CF.dbd.CHF, --CH.dbd.CHCH.sub.2F,
--CH.dbd.CHCF.sub.3, --(CH.sub.2).sub.2--CH.dbd.CF.sub.2,
--CH.sub.2CH.dbd.CHCF.sub.3, or --CH.dbd.CHCF.sub.2CF.sub.3.
5. The liquid crystal compound according to claim 4, represented by
Formula (1-1-1), Formula (1-1-2), Formula (1-2-1), Formula (1-2-2),
Formula (1-3-1), Formula (1-3-2), Formula (1-4-2), Formula (1-4-3),
Formula (1-5-3) or Formula (1-6-2): ##STR00123## ##STR00124##
wherein in the formulas, R.sup.1 is a C.sub.1-20 alkyl, a
C.sub.2-21 alkenyl, a C.sub.2-21 alkynyl, a C.sub.1-19 alkoxy, a
C.sub.2-20 alkenyloxy, a C.sub.1-19 alkylthio, a C.sub.2-19
alkenylthio, or --(CH.sub.2).sub.v--CH.dbd.CF.sub.2, in which v is
0 or an integer of 1-19; L.sup.1, L.sup.2, L.sup.3, L.sup.4 and
L.sup.5 are independently hydrogen or fluorine; and X.sup.1 is
halogen, --SF.sub.5, --CF.sub.3, --(CH.sub.2).sub.2--F,
--CF.sub.2CH.sub.2F, --CF.sub.2CHF.sub.2, --CH.sub.2CF.sub.3,
--CF.sub.2CF.sub.3, --(CH.sub.2).sub.3--F, --(CF.sub.2).sub.3--F,
--CF.sub.2CHFCF.sub.3, --CHFCF.sub.2CF.sub.3,
--(CH.sub.2).sub.4--F, --(CF.sub.2).sub.4--F,
--(CH.sub.2).sub.5--F, --(CF.sub.2).sub.5--F, --OCH.sub.2F,
--OCHF.sub.2, --O--(CH.sub.2).sub.2--F, --OCF.sub.2CH.sub.2F,
--OCF.sub.2CHF.sub.2, --OCH.sub.2CF.sub.3,
--O--(CH.sub.2).sub.3--F, --O--(CF.sub.2).sub.3--F,
--OCF.sub.2CHFCF.sub.3, --OCHFCF.sub.2CF.sub.3,
--O(CH.sub.2).sub.4--F, --O--(CF.sub.2).sub.4--F,
--O--(CH.sub.2).sub.5--F, --O--(CF.sub.2).sub.5--F, --CH.dbd.CHF,
--CH.dbd.CF.sub.2, --CF.dbd.CHF, --CH.dbd.CHCH.sub.2F,
--CH.dbd.CHCF.sub.3, --(CH.sub.2).sub.2--CH.dbd.CF.sub.2,
--CH.sub.2CH.dbd.CHCF.sub.3, or --CH.dbd.CHCF.sub.2CF.sub.3.
6. The liquid crystal compound according to claim 5, represented by
Formula (1-1-2), Formula (1-2-2), Formula (1-4-3) or Formula
(1-5-3).
7. The liquid crystal compound according claim 1, wherein L.sup.I
is hydrogen.
8. The liquid crystal compound according claim 1, wherein L.sup.1
is fluorine.
9. The liquid crystal compound according to claim 1, wherein both
L4 and L5 are fluorine, and X1 is fluorine, chlorine, --OCF.sub.3
or --CF.sub.3.
10. A liquid crystal compound, represented by Formula (1-4-3-1),
Formula (1-1-2-1), Formula (1-5-3-1), Formula (1-2-2-1) or Formula
(1-6-2-1): ##STR00125## wherein in the formulas, R.sup.1 is a
C.sub.1-20 alkyl or a C.sub.2-20 alkenyl.
11. A liquid crystal composition, comprising the compound according
to claim 1 and a chiral reagent, and exhibiting an optically
isotropic liquid crystal phase.
12. The liquid crystal composition according to claim 11, further
comprising at least one compound selected from the group consisting
of the compounds represented by Formula (2), Formula (3) and
Formula (4): ##STR00126## wherein in the formulas, R.sup.2 is a
C.sub.1-10 alkyl or a C.sub.2-10 alkenyl, wherein arbitrary
hydrogen in the alkyl and the alkenyl may be substituted with
fluorine, and arbitrary --CH.sub.2-- in the alkyl and the alkenyl
may be substituted with --O--; X.sup.2 is fluorine, chlorine,
--OCF.sub.3, --OCHF.sub.2, --CF.sub.3, --CHF.sub.2, --CH.sub.2F,
--OCF.sub.2CHF.sub.2 or --OCF.sub.2CHFCF.sub.3; rings B.sup.1,
B.sup.2 and B.sup.3 are independently 1,4-cyclohexylene,
1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl,
tetrahydropyran-2,5-diyl, 1,4-phenylene, naphthalene-2,6-diyl,
1,4-phenylene in which arbitrary hydrogen is substituted with
fluorine, or naphthalene-2,6-diyl in which arbitrary hydrogen is
substituted with fluorine or chlorine; Z.sup.7 and Z.sup.8 are
independently --(CH.sub.2).sub.2--, --(CH.sub.2).sub.4--, --COO--,
--CF.sub.2O--, --OCF.sub.2--, --CH.dbd.CH--, --CH.sub.2O-- or a
single bond; and L.sup.6 and L.sup.7 are independently hydrogen or
fluorine.
13. The liquid crystal composition according to claim 11, further
comprising at least one compound selected from the group consisting
of the compounds represented by Formula (5): ##STR00127## wherein
in the formula, R.sup.3 is a C.sub.1-10 alkyl or a C.sub.2-10
alkenyl, wherein arbitrary hydrogen in the alkyl and the alkenyl
may be substituted with fluorine, and arbitrary --CH.sub.2-- in the
alkyl and the alkenyl may be substituted with --O--; X.sup.3 is
--C.ident.N or --C.ident.C--C.ident.N; ring C.sup.1, ring C.sup.2
and ring C.sup.3 are independently 1,4-cyclohexylene,
1,4-phenylene, 1,4-phenylene in which arbitrary hydrogen is
substituted with fluorine, naphthalene-2,6-diyl,
naphthalene-2,6-diyl in which arbitrary hydrogen is substituted
with fluorine or chlorine, 1,3-dioxane-2,5-diyl,
tetrahydropyran-2,5-diyl, or pyrimidine-2,5-diyl; Z.sup.9 is
--(CH.sub.2).sub.2--, --COO--, --CF.sub.2O--, --OCF.sub.2--,
--CH.sub.2O-- or a single bond; L.sup.8 and L.sup.9 are
independently hydrogen or fluorine; and r is 1 or 2, s is 0 or 1,
r+s=0, 1 or 2.
14. The liquid crystal composition according to claim 11, further
comprising at least one compound selected from the group consisting
of the compounds represented by Formula (6): ##STR00128## wherein
in the formula, R.sup.4 and R.sup.5 are independently a C.sub.1-10
alkyl or a C.sub.2-10 alkenyl, wherein arbitrary hydrogen in the
alkyl and the alkenyl may be substituted with fluorine, and
arbitrary --CH.sub.2-- in the alkyl and the alkenyl may be
substituted with --O--; ring D.sup.1, ring D.sup.2 and ring D.sup.3
are independently 1,4-cyclohexylene, pyrimidine-2,5-diyl,
1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene, or
2,5-difluoro-1,4-phenylene; and Z.sup.10 is --C.ident.C--, --COO--,
--(CH.sub.2).sub.2--, --CH.dbd.CH-- or a single bond.
15. The liquid crystal composition according to claim 12, further
comprising at least one compound selected from the group consisting
of the compounds represented by Formula (5): ##STR00129## wherein
in the formula, R.sup.3 is a C.sub.1-10 alkyl or a C.sub.2-10
alkenyl, wherein arbitrary hydrogen in the alkyl and the alkenyl
may be substituted with fluorine, and arbitrary --CH.sub.2-- in the
alkyl and the alkenyl may be substituted with --O--; X.sup.3 is
--.ident.N or --C.ident.C--C.ident.N; ring C.sup.1, ring C.sup.2
and ring C.sup.3 are independently 1,4-cyclohexylene,
1,4-phenylene, 1,4-phenylene in which arbitrary hydrogen is
substituted with fluorine, naphthalene-2,6-diyl,
naphthalene-2,6-diyl in which arbitrary hydrogen is substituted
with fluorine or chlorine, 1,3-dioxane-2,5-diyl,
tetrahydropyran-2,5-diyl, or pyrimidine-2,5-diyl; Z.sup.9 is
--(CH.sub.2).sub.2--, --COO--, --CF.sub.2O--, --CH.sub.2O-- or a
single bond; L.sup.8 and L.sup.9 are independently hydrogen or
fluorine; and r is 1 or 2, s is 0 or 1, r+s=0, 1 or 2.
16. The liquid crystal composition according to claim 12, further
comprising at least one compound selected from the group consisting
of the compounds represented by Formula (6): ##STR00130## wherein
in the formula, R.sup.4 and R.sup.5 are independently a C.sub.1-10
alkyl or a C.sub.2-10 alkenyl, wherein arbitrary hydrogen in the
alkyl and the alkenyl may be substituted with fluorine, and
arbitrary --CH.sub.2-- in the alkyl and the alkenyl may be
substituted with --O--; ring D.sup.1, ring D.sup.2 and ring D.sup.3
are independently 1,4-cyclohexylene, pyrimidine-2,5-diyl,
1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene, or
2,5-difluoro-1,4-phenylene; and Z.sup.10 is --C.ident.C--, --COO--,
--(CH.sub.2).sub.2--, --CH.dbd.CH-- or a single bond.
17. The liquid crystal composition according to claim 13, further
comprising at least one compound selected from the group consisting
of the compounds represented by Formula (6): ##STR00131## wherein
in the formula, R.sup.4 and R.sup.5 are independently a C.sub.1-10
alkyl or a C.sub.2-10 alkenyl, wherein arbitrary hydrogen in the
alkyl and the alkenyl may be substituted with fluorine, and
arbitrary --CH.sub.2-- in the alkyl and the alkenyl may be
substituted with --O--; ring D.sup.1, ring D.sup.2 and ring D.sup.3
are independently 1,4-cyclohexylene, pyrimidine-2,5-diyl,
1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene, or
2,5-difluoro-1,4-phenylene; and Z.sup.10 is --C.ident.C--, --COO--,
--(CH.sub.9).sub.2--, --CH.dbd.CH-- or a single bond.
18. The liquid crystal composition according to claim 11, further
comprising at least one compound selected from the group consisting
of the compounds represented by Formula (7), Formula (8), Formula
(9) and Formula (10): ##STR00132## wherein in the formulas, R.sup.6
is a C.sub.1-10 alkyl, a C.sub.2-10 alkenyl, or a C.sub.2-10
alkynyl, wherein arbitrary hydrogen in the alkyl, the alkenyl and
the alkynyl may be substituted with fluorine, and arbitrary
--CH.sub.2-- in the alkyl, the alkenyl and the alkynyl may be
substituted with --O--; X.sup.4 is fluorine, chlorine, --SF.sub.5,
--OCF.sub.3, --OCHF.sub.2, --CF.sub.3, --CHF.sub.2, --CH.sub.2F,
--OCF.sub.2CHF.sub.2 or --OCF.sub.2CHFCF.sub.3; ring E.sup.1, ring
E.sup.2, ring E.sup.3 and ring E.sup.4 are independently
1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl,
tetrahydropyran-2,5-diyl, 1,4-phenylene, naphthalene-2,6-diyl,
1,4-phenylene in which arbitrary hydrogen is substituted with
fluorine or chlorine, or naphthalene-2,6-diyl in which arbitrary
hydrogen is substituted with fluorine or chlorine; Z.sup.11,
Z.sup.12 and Z.sup.13 are independently --(CH.sub.2).sub.2--,
--(CH.sub.2).sub.4--, --COO--, --CF.sub.2O--, --OCF.sub.2--,
--CH.dbd.CH--, --CH.sub.2O--, or a single bond, provided that when
any one of ring E.sup.1, ring E.sup.2, ring E.sup.3, and ring
E.sup.4 is 3-chloro-5-fluoro-1,4-phenylene, Z.sup.11, Z.sup.12 and
Z.sup.13 are not --CF.sub.2O--; and L.sup.10 and L.sup.11 are
independently hydrogen or fluorine.
19. The liquid crystal composition according to claim 11, further
comprising at least one compound selected from the group consisting
of the compounds represented by Formula (11): ##STR00133## wherein
in the formula, R.sup.7 is a C.sub.1-10 alkyl, a C.sub.2-10
alkenyl, or a C.sub.2-10 alkynyl, wherein arbitrary hydrogen in the
alkyl, the alkenyl and the alkynyl may be substituted with
fluorine, and arbitrary --CH.sub.2-- in the alkyl, the alkenyl and
the alkynyl may be substituted with --O--; X.sup.5 is --C.ident.N,
--N.dbd.C.dbd.S or --C.ident.C--C.ident.N; ring F.sup.1, ring
F.sup.2 and ring F.sup.3 are independently 1,4-cyclohexylene,
1,4-phenylene, 1,4-phenylene in which arbitrary hydrogen is
substituted with fluorine or chlorine, naphthalene-2,6-diyl,
naphthalene-2,6-diyl in which arbitrary hydrogen is substituted
with fluorine or chlorine, 1,3-dioxane-2,5-diyl,
tetrahydropyran-2,5-diyl, or pyrimidine-2,5-diyl; Z.sup.14 is
--(CH.sub.2).sub.2--, --COO--, --CF.sub.2O--, --OCF.sub.2--,
--C.ident.C--, --CH.sub.2O-- or a single bond; L.sup.12 and
L.sup.13 are independently hydrogen or fluorine; and aa is 0, 1 or
2, ab is 0 or 1, aa+ab is 0, 1 or 2.
20. The liquid crystal composition according to claim 11,
comprising at least one antioxidant and/or UV absorber.
21. The liquid crystal composition according to claim 11, wherein
the optically isotropic liquid crystal phase does not exhibit two
or more colors of diffracted light.
22. The liquid crystal composition according to claim 11, wherein
the optically isotropic liquid crystal phase exhibits two or more
colors of diffracted light.
23. The liquid crystal composition according to claim 21, obtained
by adding a chiral reagent into a composition having a temperature
difference between an upper-limit temperature and a lower-limit
temperature of 3.degree. C.-150.degree. C. of co-existence of a
chiral nematic phase and a non-liquid crystal isotropic phase.
24. The liquid crystal composition according to claim 21, obtained
by adding a chiral reagent into a composition having a temperature
difference between an upper-limit temperature and a lower-limit
temperature of 5.degree. C.-150.degree. C. of co-existence of a
chiral nematic phase and a non-liquid crystal isotropic phase.
25. The liquid crystal composition according to claim 21, obtained
by adding a chiral reagent into a composition having a temperature
difference between an upper-limit temperature and a lower-limit
temperature of 3.degree. C.-150.degree. C. of co-existence of a
nematic phase and a non-liquid crystal isotropic phase.
26. The liquid crystal composition according claim 11, wherein the
content of the chiral reagent is 1-40 wt % based on the total
weight of the liquid crystal composition.
27. The liquid crystal composition according to claim 11, wherein
the content of the chiral reagent is 5-15 wt % based on the total
weight of the liquid crystal composition.
28. The liquid crystal composition according to claim 26,
exhibiting a chiral nematic phase at any temperature in the range
of 70.degree. C. to -20.degree. C., and having a helical pitch of
700 nm or less within at least a part of the temperatures
range.
29. The liquid crystal composition according to claim 26, wherein
the chiral reagent comprises at least one compound selected from
the group consisting of compounds represented by Formulas (K1) to
(K5): ##STR00134## wherein in formulas (K1) to (K5), R.sup.K is
independently hydrogen, halogen, --C.ident.N, --N.dbd.C.dbd.O,
--N.dbd.C.dbd.S, or a C.sub.1-20 alkyl, wherein arbitrary
--CH.sub.2-- in the alkyl may be substituted with --O--, --S--,
--COO--, --OCO--, --CH.dbd.CH--, --CF.dbd.CF-- or --C.ident.C--,
and arbitrary hydrogen in the alkyl may be substituted with
halogen; A is independently aromatic or non-aromatic 3 to
8-memebered ring, or a fused ring of 9 or more carbons, wherein
arbitrary hydrogen in the rings may be substituted with halogen, a
C.sub.1-3 alkyl, or a C.sub.1-3 haloalkyl, --CH.sub.2-- in the
rings may be substituted with --O--, --S-- or --NH--, --CH.dbd. in
the rings may be substituted with --N.dbd.; B is independently
hydrogen, halogen, a C.sub.1-3 alkyl, a C.sub.1-3 haloalkyl,
aromatic or a non-aromatic 3 to 8-memebered ring, or a fused ring
of 9 or more carbons, wherein arbitrary hydrogen in the rings may
be substituted with halogen, a C.sub.1-3 alkyl, or a C.sub.1-3
haloalkyl, --CH.sub.2-- in the rings may be substituted with --O--,
--S-- or --NH--, and --CH.dbd. in the rings may be substituted with
--N.dbd.; Z is independently a single bond, or a C.sub.1-8
alkylene, wherein arbitrary --CH.sub.2-- in the alkylene maybe
substituted with --O--, --S--, --COO--, --CSO--, --OCS--,
--N.dbd.CH--, --CH.dbd.CH--, --CF.dbd.CF-- or and arbitrary
hydrogen in the alkylene may be substituted with halogen; X is a
single bond, --COO--, --COO--, --CH.sub.2O--, --OCH.sub.2--,
--OCF.sub.2--, or --CH.sub.2CH.sub.2--; and mK is an integer of
1-4.
30. The liquid crystal composition according to claim 26, wherein
the chiral agent comprises at least one compound selected from the
group consisting of compounds represented by Formulas (K2-1) to
(K2-8), Formulas (K4-1) to (K4-6) and Formulas (K5-1) to (K5-3):
##STR00135## ##STR00136## ##STR00137## wherein in the formulas,
R.sup.K is independently a C.sub.3-10 alkyl, wherein --CH.sub.2--
adjacent to a ring in the alkyl may be substituted with --O--, and
arbitrary --CH.sub.2-- in the alkyl may be substituted with
--CH.dbd.CH--.
31. A mixture, comprising the liquid crystal composition according
to claim 11 and a polymerizable monomer.
32. The mixture according to claim 31, wherein the polymerizable
monomer is a photopolymerizable monomer or a thermal-polymerizable
monomer.
33. A polymer/liquid crystal composite material, obtained by
polymerizing the mixture comprising the liquid crystal composition
according to claim 11 and a polymerizable monomer, for use in a
device driven in an optically isotropic liquid crystal phase.
34. The polymer/liquid crystal composite material according to
claim 33, obtained by polymerizing the mixture comprising the
liquid crystal composition according to claim 11 and a
polymerizable monomer in a non-liquid crystal isotropic phase or an
optically isotropic liquid crystal phase.
35. The polymer/liquid crystal composite material according to
claim 33, wherein the polymer contained in the polymer/liquid
crystal composite material has a mesogen moiety.
36. The polymer/liquid crystal composite material according to
claim 33, wherein the polymer contained in the polymer/liquid
crystal composite material has a cross-linked structure.
37. The polymer/liquid crystal composite material according to
claim 33, wherein the content of the liquid crystal composition is
60-99 wt %, and the content of the polymer is 1-40 wt %.
38. An optical device, comprising a liquid crystal medium arranged
between substrates having electrodes arranged on either or both
surfaces thereof and an electric field-applying means for applying
an electric field to the liquid crystal medium via the electrodes,
wherein the liquid crystal medium is the liquid crystal composition
according to claim 11, wherein a content of the chiral reagent is
1-40 wt % based on the total weight of the liquid crystal
composition or the polymer/liquid crystal composite material
obtained by polymerizing the mixture comprising the liquid crystal
composition according to claim 11 and a polymerizable monomer, for
use in a device driven in an optically isotropic liquid crystal
phase.
39. An optical device, comprising a set of substrates having
electrodes arranged on either or both surfaces thereof and at least
one being transparent, a liquid crystal medium arranged between the
substrates, a polarizer arranged outside of the substrates, and an
electric field-applying means for applying an electric field to the
liquid crystal medium via the electrodes, wherein the liquid
crystal medium is the liquid crystal composition according to claim
11, wherein a content of the chiral reagent is 1-40 wt % based on
the total weight of the liquid crystal composition or the
polymer/liquid crystal composite material obtained by polymerizing
the mixture comprising the liquid crystal composition according to
claim 11 and a polymerizable monomer, for use in a device driven in
an optically isotropic liquid crystal phase.
40. The optical device according to claim 39, wherein on at least
one of the set of substrates, the electrodes are constructed in a
manner such that an electric field is applied in at least two
directions.
41. The optical device according to claim 39, wherein on one or two
of the set of substrates arranged in parallel, the electrodes are
constructed in a manner such that an electric field is applied in
at least two directions.
42. The optical device according to claim 38, wherein the
electrodes are arranged in matrix form to form pixel electrodes,
and each pixel is provided with an active element being a thin film
transistor (TFT).
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a liquid crystal compound
useful as a material for an optical device, and a liquid crystal
medium, and in particular, to a liquid crystal compound having a
large dielectric anisotropy, a large refractive index anisotropy,
and a low melting point; and a liquid crystal medium having a
liquid crystal phase over a wide temperature range, a large
dielectric anisotropy, and a large refractive index anisotropy. In
addition, the present invention further relates to an optical
device using the liquid crystal medium, and in particular, to an
optical device that can be used over a wide temperature range and
driven at a low voltage, and can achieve a high-speed
electro-optical response.
[0003] 2. Description of Related Art
[0004] Liquid crystal display (LCD) devices containing liquid
crystal compositions are widely used as the display for clocks
calculators, word processors, and so on. These LCD devices utilize
the refractive index anisotropy and dielectric anisotropy of liquid
crystal compounds. It is known that the operation modes of the LCD
devices mainly include phase change (PC), twisted nematic (TN),
super twisted nematic (STN), bistable twisted nematic (BTN),
electrically controlled birefringence (ECB), optically compensated
bend (OCB), in-plane switching (IPS), and vertical alignment (VA)
which utilize one or more polarizers for display. Moreover, in
recent years, more attentions have been paid to the mode in which
an electric field is applied to an optically isotropic liquid
crystal phase to make the liquid crystal phase to exhibit
electrically controlled birefringence (Patent Documents 1-9, and
Non-patent Documents 1-3).
[0005] Moreover, wavelength variable filters, wavefront control
devices, liquid-crystal lenses, aberration correction devices,
aperture control devices, and optical head devices that utilize the
electrically controlled birefringence in a blue phase, as one of
the optically isotropic liquid crystal phases have been proposed
(Patent Documents 10-12).
[0006] According to the driving mode, the LCD devices can be
classified into passive matrix (PM) type and active matrix (AM)
type. The PM type is further classified into static type and
multiplex type, and the AM type is further classified into thin
film transistor (TFT) type, metal insulator metal (MIM) type and so
on.
[0007] Such LCD devices contain a liquid crystal composition having
suitable physical properties. To improve the characteristics of an
LCD device, the liquid crystal composition preferably has suitable
physical properties. A liquid crystal compound as a component of a
liquid crystal composition requires to have the following general
physical properties:
[0008] (1) stable chemical and physical properties;
[0009] (2) a high clear point (i.e., phase transition temperature
from the liquid crystal phase to the isotropic phase);
[0010] (3) a low lower-limit temperature of a liquid crystal phase
(i.e., an optically isotropic liquid crystal phase such as nematic
phase, cholesteric phase, smectic phase, and blue phase);
[0011] (4) excellent compatibility with other liquid crystal
compounds;
[0012] (5) a suitable dielectric anisotropy; and
[0013] (6) a suitable refractive index anisotropy.
[0014] Particularly, for an optically isotropic liquid crystal
phase, a liquid crystal compound having a large dielectric
anisotropy and a large refractive index anisotropy is preferred,
from the viewpoint of lowering the driving voltage.
[0015] When a liquid crystal composition containing a liquid
crystal compound having stable chemical and physical properties as
described in (1) is used in an LCD device, the voltage holding
ratio is improved.
[0016] Further, a liquid crystal composition containing a liquid
crystal compound having a high clear point or a low lower-limit
temperature of a liquid crystal phase as described in (2) and (3),
can have a nematic phase or an optically isotropic liquid crystal
phase over an expanded temperature range, thus being capable of
being used in a display device over a wide temperature range. A
liquid crystal composition is generally prepared by mixing a liquid
crystal compound with a number of other liquid crystal compounds,
so as to exhibit better properties that are difficult to develop by
a single compound. Therefore, a liquid crystal compound having good
compatibility with other liquid crystal compounds as described in
(4) is preferably used in an LCD device. In recent years, LCD
devices with superior properties, especially display performances,
for example, contrast, display capacity, and response time, are
especially required in the industry. In addition, regarding the
liquid crystal material that is being used, a liquid crystal
composition having a low driving voltage is required. Furthermore,
in order to drive an optical device driven in an optically
isotropic liquid crystal phase, a liquid crystal compound with a
large dielectric anisotropy and a large refractive index anisotropy
is preferred.
[0017] It was reported that chlorobenzene derivatives analogous to
the compound of the present invention have large dielectric
anisotropy and large refractive index anisotropy (Patent Document
13), but a compound having a chlorobenzene moiety and the excellent
properties of the compound according to the present invention have
not been reported. Moreover, as for the optically isotropic
polymer/liquid crystal composite material disclosed in Patent
Documents 1-3 and Non-patent Documents 1-3, the device needs to
operate at a high voltage. Although an optically isotropic liquid
crystal composition and a polymer/liquid crystal composite
material, which are expected to have an operation voltage lower
than the voltages as disclosed in Patent Documents 1-3 and
Non-patent Documents 1-3, are disclosed in Patent Documents 4-9, an
optically isotropic liquid crystal composition containing a
compound having a chlorobenzene moiety of the present invention and
polymer/liquid crystal composite material were not disclosed.
DOCUMENTS IN THE PRIOR ART
Patent Documents
[0018] Patent Document 1: Japanese Patent Publication No.
2003-327966 [0019] Patent Document 2: International Publication No.
2005/90520 [0020] Patent Document 3: Japanese Patent Publication
No. 2005-336477 [0021] Patent Document 4: Japanese Patent
Publication No. 2006-89622 [0022] Patent Document 5: Japanese
Patent Publication No. 2006-299084 [0023] Patent Document 6:
Japanese Patent Publication No. 2006-506477 [0024] Patent Document
7: Japanese Patent Publication No. 2006-506515 [0025] Patent
Document 8: International Publication No. 2006/063662 [0026] Patent
Document 9: Japanese Patent Publication No. 2006-225655 [0027]
Patent Document 10: Japanese Patent Publication No. 2005-157109
[0028] Patent Document 11: International Publication No. 2005/80529
[0029] Patent Document 12: Japanese Patent Publication No.
2006-127707 [0030] Patent Document 13: International Publication
No. 1998/023561
Non-patent Documents
[0030] [0031] Non-patent Document 1: Nature Materials, 1, 64,
(2002) [0032] Non-patent Document 2: Adv. Mater., 17, 96, (2005)
[0033] Non-patent Document 3: Journal of the SID, 14, 551,
(2006)
SUMMARY OF THE INVENTION
Technical Problems to Be Solved in the Invention
[0034] Accordingly, the present invention is directed to a liquid
crystal compound, which is stable to heat and light, and has a
large refractive index anisotropy, a large dielectric anisotropy,
and a low melting point. The present invention is also directed to
a liquid crystal medium, which is stable to heat and light, and has
a liquid crystal phase over a wide temperature range, a large
refractive index anisotropy, a large dielectric anisotropy, and
also an optically isotropic liquid crystal phase. The present
invention is further directed to various optical devices, which
contain the liquid crystal medium, can be used over a wide
temperature range, and have a short response time and a large
contrast, and a low driving voltage.
Technical Means for Solving the Technical Problems
[0035] The present invention provides a liquid crystal compound, a
liquid crystal medium (a liquid crystal composition or a
polymer/liquid crystal composite), and an optical device containing
the liquid crystal medium.
[0036] [1] A compound, represented by Formula (1):
##STR00001##
[0037] (in Formula (1), R' is hydrogen or a C.sub.1-20 alkyl,
wherein arbitrary --CH.sub.2-- in the alkyl may be substituted with
--O--, --S--, --COO--, --COO--, --CH.dbd.CH--, --CF.dbd.CF-- or
--C.ident.C--, and arbitrary hydrogen in the alkyl and the alkyl
with arbitrary --CH.sub.2-- substituted with --O--, --S--, --COO--,
--COO--, --CH.dbd.CH--, --CF.dbd.CF--, or --C.ident.C-- may be
substituted with halogen or a C.sub.1-3 alkyl; Z.sup.1, Z.sup.2,
Z.sup.3, Z.sup.4, Z.sup.5, and Z.sup.6 are independently a single
bond or --CF.sub.2O--, provided that at least one of Z.sup.1,
Z.sup.2, Z.sup.3, Z.sup.4, Z.sup.5, and Z.sup.6 is --CF.sub.2O--;
L.sup.1, L.sup.2, L.sup.3, L.sup.4, and L.sup.5 are independently
hydrogen or fluorine; X.sup.1 is halogen, --C.ident.N,
--N.dbd.C.dbd.S, --SF.sub.5 or a C.sub.1-3 alkyl in which arbitrary
hydrogen is substituted with fluorine, and arbitrary --CH.sub.2--
in the alkyl may be substituted with --O--, --S--, --CH.dbd.CH-- or
--C.ident.C--; and 1, m, n, o and p are independently 0 or 1, and
1.ltoreq.1+m+n+o+p.ltoreq.2.
[0038] [2] The liquid crystal compound according to item 1, where
in Formula (1), R.sup.1 is a C.sub.1-20 alkyl, a C.sub.2-21
alkenyl, a C.sub.2-21 alkynyl, a C.sub.1-19 alkoxy, a C.sub.2-20
alkenyloxy, a C.sub.1-19 alkylthio, a C.sub.2-19 alkenylthio, or
--(CH.sub.2).sub.v--CH.dbd.CF.sub.2, in which v is 0 or an integer
of 1-19; and X.sup.1 is halogen, --SF.sub.5, --CH.sub.2F,
--CHF.sub.2, --CF.sub.3, --(CH.sub.2).sub.2--F,
--CF.sub.2CH.sub.2F, --CF.sub.2CHF.sub.2, --CH.sub.2CF.sub.3,
--CF.sub.2CF.sub.3, --(CH.sub.2).sub.3--F, --(CF.sub.2).sub.3--F,
--CF.sub.2CHFCF.sub.3, --CHFCF.sub.2CF.sub.3,
--(CH.sub.2).sub.4--F, --(CF.sub.2).sub.4--F,
--(CH.sub.2).sub.5--F, --(CF.sub.2).sub.5--F, --OCH.sub.2F,
--OCHF.sub.2, --OCF.sub.3, --O--(CH.sub.2).sub.2--F,
--OCF.sub.2CH.sub.2F, --OCF.sub.2CHF.sub.2, --OCH.sub.2CF.sub.3,
--O--(CH.sub.2).sub.3--F, --O--(CF.sub.2).sub.3--F,
--OCF.sub.2CHFCF.sub.3, --OCHFCF.sub.2CF.sub.3,
--O(CH.sub.2).sub.4--F, --O--(CF.sub.2).sub.4--F,
--O--(CH.sub.2).sub.5--F, --O--(CF.sub.2).sub.5--F, --CH.dbd.CHF,
--CH.dbd.CF.sub.2, --CF.dbd.CHF, --CH.dbd.CHCH.sub.2F,
--CH.dbd.CHCF.sub.3, --(CH.sub.2).sub.2--CH.dbd.CF.sub.2,
--CH.sub.2CH.dbd.CHCF.sub.3, or --CH.dbd.CHCF.sub.2CF.sub.3.
[0039] [3] The liquid crystal compound according to item 1 or 2,
wherein in Formula (1), R.sup.1 is a C.sub.1-20 alkyl or a
C.sub.2-21 alkenyl.
[0040] [4] The liquid crystal compound according to any one of
items 1 to 3, represented by Formula (1-1), Formula (1-2), Formula
(1-3), Formula (1-4), Formula (1-5) or Formula (1-6).
##STR00002##
[0041] (in the formulas, R.sup.1 is a C.sub.1-20 alkyl, a
C.sub.2-21 alkenyl, a C.sub.2-21 alkynyl, a C.sub.1-19 alkoxy, a
C.sub.2-20 alkenyloxy, a C.sub.1-19 alkylthio, a C.sub.2-19
alkenylthio, or --(CH.sub.2).sub.v--CH.dbd.CF.sub.2, in which v is
0 or an integer of 1-19; Z.sup.1, Z.sup.2, Z.sup.3, Z.sup.4,
Z.sup.5 and Z.sup.6 are independently a single bond or
--CF.sub.2O--, provided that at least one of Z.sup.1, Z.sup.2,
Z.sup.3, Z.sup.4, Z.sup.5 and Z.sup.6 is --CF.sub.2O--; L.sup.1,
L.sup.2, L.sup.3, L.sup.4 and L.sup.5 are independently hydrogen or
fluorine; and X.sup.1 is halogen, --SF.sub.5, --CH.sub.2F,
--CHF.sub.2, --CF.sub.3, --(CH.sub.2).sub.2--F,
--CF.sub.2CH.sub.2F, --CF.sub.2CHF.sub.2, --CH.sub.2CF.sub.3,
--CF.sub.2CF.sub.3, --(CH.sub.2).sub.3--F, --(CF.sub.2).sub.3--F,
--CF.sub.2CHFCF.sub.3, --CHFCF.sub.2CF.sub.3,
--(CH.sub.2).sub.4--F, --(CF.sub.2).sub.4--F,
--(CH.sub.2).sub.5--F, --(CF.sub.2).sub.5--F, --OCH.sub.2F,
--OCHF.sub.2, --OCF.sub.3, --O--(CH.sub.2).sub.2--F,
--OCF.sub.2CH.sub.2F, --OCF.sub.2CHF.sub.2, --OCH.sub.2CF.sub.3,
--O--(CH.sub.2).sub.3--F, --O--(CF.sub.2).sub.3--F,
--OCF.sub.2CHFCF.sub.3, --OCHFCF.sub.2CF.sub.3,
--O(CH.sub.2).sub.4--F, --O--(CF.sub.2).sub.4--F,
--O--(CH.sub.2).sub.5--F, --O--(CF.sub.2).sub.5--F, --CH.dbd.CHF,
--CH.dbd.CF.sub.2, --CF.dbd.CHF, --CH.dbd.CHCH.sub.2F,
--CH.dbd.CHCF.sub.3, --(CH.sub.2).sub.2--CH.dbd.CF.sub.2,
--CH.sub.2CH.dbd.CHCF.sub.3, or --CH.dbd.CHCF.sub.2CF.sub.3.)
[0042] [5] The liquid crystal compound according to item 4,
represented by Formula (1-1-1), Formula (1-1-2), Formula (1-2-1),
Formula (1-2-2), Formula (1-3-1), Formula (1-3-2), Formula (1-4-2),
Formula (1-4-3), Formula (1-5-3) or Formula (1-6-2).
##STR00003## ##STR00004##
[0043] (in the formulas, R.sup.1 is a C.sub.1-20 alkyl, a
C.sub.2-21 alkenyl, a C.sub.2-21 alkynyl, a C.sub.1-19 alkoxy, a
C.sub.2-20 alkenyloxy, a C.sub.1-19 alkylthio, a C.sub.2-19
alkenylthio, or --(CH.sub.2).sub.v--CH.dbd.CF.sub.2, in which v is
0 or an integer of 1-19; L.sup.1, L.sup.2, L.sup.3, L.sup.4 and
L.sup.5 are independently hydrogen or fluorine; and X.sup.1 is
halogen, --SF.sub.5, --CH.sub.2F, --CHF.sub.2, --CF.sub.3,
--(CH.sub.2).sub.2--F, --CF.sub.2CH.sub.2F, --CF.sub.2CHF.sub.2,
--CH.sub.2CF.sub.3, --CF.sub.2CF.sub.3, --(CH.sub.2).sub.3--F,
--(CF.sub.2).sub.3--F, --CF.sub.2CHFCF.sub.3,
--CHFCF.sub.2CF.sub.3, --(CH.sub.2).sub.4--F,
--(CF.sub.2).sub.4--F, --(CH.sub.2).sub.5--F,
--(CF.sub.2).sub.5--F, --OCH.sub.2F, --OCHF.sub.2, --OCF.sub.3,
--O--(CH.sub.2).sub.2--F, --OCF.sub.2CH.sub.2F,
--OCF.sub.2CHF.sub.2, --OCH.sub.2CF.sub.3,
--O--(CH.sub.2).sub.3--F, --O--(CF.sub.2).sub.3--F,
--OCF.sub.2CHFCF.sub.3, --OCHFCF.sub.2CF.sub.3,
--O(CH.sub.2).sub.4--F, --O--(CF.sub.2).sub.4--F,
--O--(CH.sub.2).sub.5--F, --O--(CF.sub.2).sub.5--F, --CH.dbd.CHF,
--CH.dbd.CF.sub.2, --CF.dbd.CHF, --CH.dbd.CHCH.sub.2F,
--CH.dbd.CHCF.sub.3, --(CH.sub.2).sub.2--CH.dbd.CF.sub.2,
--CH.sub.2CH.dbd.CHCF.sub.3, or --CH.dbd.CHCF.sub.2CF.sub.3.).
[0044] [6] The liquid crystal compound according to item 4,
represented by Formula (1-1-2), Formula (1-2-2), Formula (1-4-3) or
Formula (1-5-3).
[0045] [7] The liquid crystal compound according to any one of
items 1 to 6, where L.sup.1 is hydrogen.
[0046] [8] The liquid crystal compound according to any one of
items 1 to 6, where L.sup.1 is fluorine.
[0047] [9] The liquid crystal compound according to any one of
items 1 to 8, where both L4 and L5 are fluorine, and X1 is
fluorine, chlorine, --OCF.sub.3 or --CF.sub.3.
[0048] [10] A liquid crystal compound, represented by Formula
(1-4-3-1), Formula (1-1-2-1), Formula (1-5-3-1), Formula (1-2-2-1)
or Formula (1-6-2-1).
##STR00005##
[0049] (in the formulas, R.sup.1 is a C.sub.1-20 alkyl or a
C.sub.2-20 alkenyl.)
[0050] [11] A liquid crystal composition, containing the compound
according to any one of items 1 to 10 and a chiral reagent, and
exhibiting an optically isotropic liquid crystal phase.
[0051] [12] The liquid crystal composition according to item 11,
further containing at least one compound selected from the group
consisting of the compounds represented by Formula (2), Formula (3)
and Formula (4).
##STR00006##
[0052] (in the formulas, R.sup.2 is a C.sub.1-10 alkyl or a
C.sub.2-10 alkenyl, wherein arbitrary hydrogen in the alkyl and the
alkenyl may be substituted with fluorine, and arbitrary
--CH.sub.2-- in the alkyl and the alkenyl may be substituted with
--O--; X.sup.2 is fluorine, chlorine, --OCF.sub.3, --OCHF.sub.2,
--CF.sub.3, --CHF.sub.2, --CH.sub.2F, --OCF.sub.2CHF.sub.2 or
--OCF.sub.2CHFCF.sub.3; ring B.sup.1, ring B.sup.2 and ring B.sup.3
are independently 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl,
pyrimidine-2,5-diyl, tetrahydropyran-2,5-diyl, 1,4-phenylene,
naphthalene-2,6-diyl, 1,4-phenylene in which arbitrary hydrogen is
substituted with fluorine, or naphthalene-2,6-diyl in which
arbitrary hydrogen is substituted with fluorine or chlorine;
Z.sup.7 and Z.sup.8 are independently --(CH.sub.2).sub.2--,
--(CH.sub.2).sub.4--, --COO--, --CF.sub.2O--, --OCF.sub.2--,
--CH.ident.CH--, --C.ident.C--, --CH.sub.2O-- or a single bond; and
L.sup.6 and L.sup.7 are independently hydrogen or fluorine.)
[0053] [13] The liquid crystal composition according to item 11,
further containing at least one compound selected from the group
consisting of the compounds represented by Formula (5).
##STR00007##
[0054] (in the formula, R.sup.3 is a C.sub.1-10 alkyl or a
C.sub.2-10 alkenyl, wherein arbitrary hydrogen in the alkyl and the
alkenyl may be substituted with fluorine, and arbitrary
--CH.sub.2-- in the alkyl and the alkenyl may be substituted with
--O--; X.sup.3 is --C.ident.N or --C.ident.C--C.ident.N; ring
C.sup.1, ring C.sup.2 and ring C.sup.3 are independently
1,4-cyclohexylene, 1,4-phenylene, 1,4-phenylene in which arbitrary
hydrogen is substituted with fluorine, naphthalene-2,6-diyl,
naphthalene-2,6-diyl in which arbitrary hydrogen is substituted
with fluorine or chlorine, 1,3-dioxane-2,5-diyl,
tetrahydropyran-2,5-diyl, or pyrimidine-2,5-diyl; Z.sup.9 is
--(CH.sub.2).sub.2--, --COO--, --CF.sub.2O--, --OCF.sub.2--,
--C.ident.C--, --CH.sub.2O-- or a single bond; L.sup.8 and L.sup.9
are independently hydrogen or fluorine; and r is 1 or 2, s is 0 or
1, r+s=0, 1 or 2.)
[0055] [14] The liquid crystal composition according to item 11,
further containing at least one compound selected from the group
consisting of the compounds represented by Formula (6).
##STR00008##
[0056] (in the formula, R.sup.4 and R.sup.5 are independently a
C.sub.1-10 alkyl or a C.sub.2-10 alkenyl, wherein arbitrary
hydrogen in the alkyl and the alkenyl may be substituted with
fluorine, and arbitrary --CH.sub.2-- in the alkyl and the alkenyl
may be substituted with --O--; ring D.sup.1, ring D.sup.2 and ring
D.sup.3 are independently 1,4-cyclohexylene, pyrimidine-2,5-diyl,
1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene, or
2,5-difluoro-1,4-phenylene; and Z.sup.10 is --C.ident.C--, --COO--,
--(CH.sub.2).sub.2--, --CH.dbd.CH-- or a single bond.)
[0057] [15] The liquid crystal composition according to item 12,
further containing at least one compound selected from the group
consisting of the compounds represented by Formula (5) according to
item 13.
[0058] [16] The liquid crystal composition according to item 12,
further containing at least one compound selected from the group
consisting of the compounds represented by Formula (6).
[0059] [17] The liquid crystal composition according to item 13,
further containing at least one compound selected from the group
consisting of the compounds represented by Formula (6).
[0060] [18] The liquid crystal composition according to item 11,
further containing at least one compound selected from the group
consisting of the compounds represented by Formula (7), Formula
(8), Formula (9) and Formula (10).
##STR00009##
[0061] (in the formulas, R.sup.6 is a C.sub.1-10 alkyl, a
C.sub.2-10 alkenyl, or a C.sub.2-10 alkynyl, wherein arbitrary
hydrogen in the alkyl, the alkenyl and the alkynyl may be
substituted with fluorine, and arbitrary --CH.sub.2-- in the alkyl,
the alkenyl and the alkynyl may be substituted with --O--; X.sup.4
is fluorine, chlorine, --SF.sub.5, --OCF.sub.3, --OCHF.sub.2,
--CF.sub.3, --CHF.sub.2, --CH.sub.2F, --OCF.sub.2CHF.sub.2 or
--OCF.sub.2CHFCF.sub.3; ring E.sup.1, ring E.sup.2, ring E.sup.3
and ring E.sup.4 are independently 1,4-cyclohexylene,
1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl,
tetrahydropyran-2,5-diyl, 1,4-phenylene, naphthalene-2,6-diyl,
1,4-phenylene in which arbitrary hydrogen is substituted with
fluorine or chlorine, or naphthalene-2,6-diyl in which arbitrary
hydrogen is substituted with fluorine or chlorine; Z.sup.11,
Z.sup.12 and Z.sup.13 are independently --(CH.sub.2).sub.2--,
--(CH.sub.2).sub.4--, --COO--, --CF.sub.2O--, --OCF.sub.2--,
--CH.dbd.CH--, --C.ident.C--, --CH.sub.2O--, or a single bond,
provided that when any one of ring E.sup.1, ring E.sup.2, ring
E.sup.3, and ring E.sup.4 is 3-chloro-5-fluoro-1,4-phenylene,
Z.sup.11, Z.sup.12 and Z.sup.13 are not --CF.sub.2O--; and L.sup.10
and L.sup.11 are independently hydrogen or fluorine.)
[0062] [19] The liquid crystal composition according to item 11,
further containing at least one compound selected from the group
consisting of the compounds represented by Formula (11).
##STR00010##
[0063] (in the formula, R.sup.7 is a C.sub.1-10 alkyl, a C.sub.2-10
alkenyl, or a C.sub.2-10 alkynyl, wherein arbitrary hydrogen in the
alkyl, the alkenyl and the alkynyl may be substituted with
fluorine, and arbitrary --CH.sub.2-- in the alkyl, the alkenyl and
the alkynyl may be substituted with --O--; X.sup.5 is --C.ident.N,
--N.dbd.C.dbd.S or --C.ident.C--C.ident.N; ring F.sup.1, ring
F.sup.2 and ring F.sup.3 are independently 1,4-cyclohexylene,
1,4-phenylene, 1,4-phenylene in which arbitrary hydrogen is
substituted with fluorine or chlorine, naphthalene-2,6-diyl,
naphthalene-2,6-diyl in which arbitrary hydrogen is substituted
with fluorine or chlorine, 1,3-dioxane-2,5-diyl,
tetrahydropyran-2,5-diyl, or pyrimidine-2,5-diyl; Z.sup.14 is
--(CH.sub.2).sub.2--, --COO--, --CF.sub.2O--, --OCF.sub.2--,
--C.ident.C--, --CH.sub.2O-- or a single bond; L.sup.12 and
L.sup.13 are independently hydrogen or fluorine; and aa is 0, 1 or
2, ab is 0 or 1, aa+ab is 0, 1 or 2.)
[0064] [20] The liquid crystal composition according to any one of
items 11 to 19, containing at least one antioxidant and/or UV
absorber.
[0065] [21] The liquid crystal composition according to any one of
items 11 to 20, where the optically isotropic liquid crystal phase
does not exhibit two or more colors of diffracted light.
[0066] [22] The liquid crystal composition according to any one of
items 11 to 20, where the optically isotropic liquid crystal phase
exhibits two or more colors of diffracted light.
[0067] [23] The liquid crystal composition according to item 21 or
22, obtained by adding a chiral reagent into a composition having a
temperature difference between an upper-limit temperature and a
lower-limit temperature of 3.degree. C.-150.degree. C. of
co-existence of a chiral nematic phase and a non-liquid crystal
isotropic phase.
[0068] [24] The liquid crystal composition according to item 21 or
22, obtained by adding a chiral reagent into a composition having a
temperature difference between an upper-limit temperature and a
lower-limit temperature of 5.degree. C.-150.degree. C. of
co-existence of a chiral nematic phase and a non-liquid crystal
isotropic phase.
[0069] [25] The liquid crystal composition according to item 21 or
22, obtained by adding a chiral reagent into a composition having a
temperature difference between an upper-limit temperature and a
lower-limit temperature of 3.degree. C.-150.degree. C. of
co-existence of a nematic phase and a non-liquid crystal isotropic
phase.
[0070] [26] The liquid crystal composition according to any one of
items 11 to 25, where the content of the chiral reagent is 1-40 wt
% based on the total weight of the liquid crystal composition.
[0071] [27] The liquid crystal composition according to any one of
items 11 to 25, where the content of the chiral reagent is 5-15 wt
% based on the total weight of the liquid crystal composition.
[0072] [28] The liquid crystal composition according to item 26 or
27, exhibiting a chiral nematic phase at any temperature in the
range of 70.degree. C. to -20.degree. C., and having a helical
pitch of 700 nm or less within at least a part of the temperatures
range.
[0073] [29] The liquid crystal composition according to any one of
items 26 to 28, where the chiral reagent includes at least one
compound selected from the group consisting of compounds
represented by Formulas (K1) to (K5).
##STR00011##
[0074] (in formulas (K1) to (K5), R.sup.K is independently
hydrogen, halogen, --C.ident.N, --N.dbd.C.dbd.O, --N.dbd.C.dbd.S,
or a C.sub.1-20 alkyl, wherein arbitrary --CH.sub.2-- in the alkyl
may be substituted with --O--, --S--, --COO--, --COO--,
--CH.dbd.CH--, --CF.dbd.CF-- or and arbitrary hydrogen in the alkyl
may be substituted with halogen; A is independently aromatic or
non-aromatic 3 to 8-memebered ring, or a fused ring of 9 or more
carbons, wherein arbitrary hydrogen in the rings may be substituted
with halogen, a C.sub.1-3 alkyl, or a C.sub.1-3 haloalkyl,
--CH.sub.2-- in the rings may be substituted with --O--, --S-- or
--NH--, --CH.dbd. in the rings may be substituted with --N.dbd.; B
is independently hydrogen, halogen, a C.sub.1-3 alkyl, a C.sub.1-3
haloalkyl, aromatic or a non-aromatic 3 to 8-memebered ring, or a
fused ring of 9 or more carbons, wherein arbitrary hydrogen in the
rings may be substituted with halogen, a C.sub.1-3 alkyl, or a
C.sub.1-3 haloalkyl, --CH.sub.2-- in the rings may be substituted
with --O--, --S-- or --NH--, and --CH.dbd. in the rings may be
substituted with --N.dbd.; Z is independently a single bond, or a
C.sub.1-8 alkylene, wherein arbitrary --CH.sub.2-- in the alkylene
may be substituted with --O--, --S--, --COO--, --COO--, --CSO--,
--OCS--, --N.dbd.N--, --CH.dbd.N--, --N.dbd.CH--, --CH.dbd.CH--,
--CF.dbd.CF-- or --C.ident.C--, and arbitrary hydrogen in the
alkylene may be substituted with halogen;
[0075] X is a single bond, --COO--, --COO--, --CH.sub.2O--,
--OCH.sub.2--, --CF.sub.2O--, --OCF.sub.2--, or
--CH.sub.2CH.sub.2--; and
[0076] mK is an integer of 1-4.)
[0077] [30] The liquid crystal composition according to any one of
items 26 to 28, where the chiral agent includes at least one
compound selected from the group consisting of compounds
represented by Formulas (K2-1) to (K2-8), Formulas (K4-1) to (K4-6)
and Formulas (K5-1) to (K5-3).
##STR00012## ##STR00013##
[0078] (in the formulas, R.sup.K is independently a C.sub.3-10
alkyl, wherein --CH.sub.2-- adjacent to a ring in the alkyl may be
substituted with --O--, and arbitrary --CH.sub.2-- in the alkyl may
be substituted with --CH.dbd.CH--.)
[0079] [31] A mixture, containing the liquid crystal composition
according to any one of items 11 to 30 and a polymerizable
monomer.
[0080] [32] The mixture according to item 31, where the
polymerizable monomer is a photopolymerizable monomer or a
thermal-polymerizable monomer.
[0081] A polymer/liquid crystal composite material, obtained by
polymerizing the mixture according to item 31 or 32, for use in a
device driven in an optically isotropic liquid crystal phase.
[0082] [34] The polymer/liquid crystal composite material according
to item 33, obtained by polymerizing the mixture according to item
31 or 32 in a non-liquid crystal isotropic phase or an optically
isotropic liquid crystal phase.
[0083] [35] The polymer/liquid crystal composite material according
to item 33 or 34, where the polymer contained in the polymer/liquid
crystal composite material has a mesogen moiety.
[0084] [36] The polymer/liquid crystal composite material according
to any one of items 33 to 35, where the polymer contained in the
polymer/liquid crystal composite material has a cross-linked
structure.
[0085] [37] The polymer/liquid crystal composite material according
to any one of items 33 to 36, where the content of the liquid
crystal composition is 60-99 wt %, and the content of the polymer
is 1-40 wt %.
[0086] [38] An optical device, including a liquid crystal medium
arranged between substrates having electrodes arranged on either or
both surfaces thereof and an electric field-applying means for
applying an electric field to the liquid crystal medium via the
electrodes, where the liquid crystal medium is the liquid crystal
composition according to any one of items 26 to 30 or the
polymer/liquid crystal composite material according to any one of
items 33 to 37.
[0087] [39] An optical device, including a set of substrates having
electrodes arranged on either or both surfaces thereof and at least
one being transparent, a liquid crystal medium arranged between the
substrates, a polarizer arranged outside of the substrates, and an
electric field-applying means for applying an electric field to the
liquid crystal medium via the electrodes, where the liquid crystal
medium is the liquid crystal composition according to any one of
items 26 to 30 or the polymer/liquid crystal composite material
according to any one of items 33 to 37.
[0088] [40] The optical device according to item 39, where on at
least one of the set of substrates, the electrodes are constructed
in a manner such that an electric field is applied in at least two
directions.
[0089] [41] The optical device according to item 39, where on one
or two of the set of substrates arranged in parallel, the
electrodes are constructed in a manner such that an electric field
is applied in at least two directions.
[0090] [42] The optical device according to any one of items 38 to
41, where the electrodes are arranged in a matrix form to form
pixel electrodes, and each pixel is provided with an active element
being a thin film transistor (TFT).
[0091] According to the present invention, the so-called liquid
crystal medium is a generic term of a liquid crystal composition
and a polymer/liquid crystal composite. Furthermore, the so-called
optical device refers to various devices using electro-optic effect
to achieve optical modulation or optical switching functions, for
example, display device (LCD device), and optical modulation device
used in optical communication systems, optical information
processing or various sensor systems. As for the optical modulation
with changes in refractive index caused by applying a voltage to an
optically isotropic liquid crystal medium, the Kerr effect is
known. The so-called Kerr effect is a phenomenon, in which the
electric birefringence value .DELTA.n (E) is proportional to the
square of the electric field E, that is, .DELTA.n
(E)=K.lamda.E.sup.2 (K=Kerr coefficient (or Kerr constant),
.lamda.: wavelength)), for a material exhibiting the Kerr effect.
Herein, the so-called electric birefringence value refers to a
refractive index anisotropy value induced by applying an electric
field to an isotropic medium.
[0092] The terms in this specification are defined as follows. The
liquid crystal compound is a generic term of compounds having a
liquid crystal phase such as nematic phase and smectic phase and
compounds having no liquid crystal phase but being useful as a
component of a liquid crystal composition. The chiral reagent is an
optically active compound, which is added to impart the necessary
twisted molecular arrangement to a liquid crystal composition. The
LCD device is a generic term of LCD panels and LCD modules. The
liquid crystal compound, the liquid crystal composition, and the
LCD device are sometimes simply referred to as the compound, the
composition, and the device, respectively. Furthermore, for
example, the upper-limit temperature of a liquid crystal phase is
the liquid crystal phase-isotropic phase transition temperature,
and sometimes only simply referred to as the clear point or the
upper-limit temperature, and the lower-limit temperature of a
liquid crystal phase is sometimes only simply referred to as the
lower-limit temperature. The compound of Formula (1) is sometimes
simply referred to as Compound (1), and this rule is also
applicable for the compound of Formula (2) and so on. In Formulas
(1)-(11), the symbols B, D, and E surrounded by hexagons,
correspond to ring B, ring D, and ring E respectively. The compound
content by percentage is weight percent (wt %) based on the total
weight of the composition. A plurality of identical symbols such as
ring A.sup.1, ring Y.sup.1, or ring B is included in the same or
different formulas; however, the groups represented by these
symbols can be the same or different.
[0093] "Arbitrary" denotes not only arbitrary position, but also
arbitrary number, except for the case where the number is 0. The
expression that arbitrary A may be substituted with B, C, or D not
only means arbitrary A may be substituted with B, arbitrary A may
be substituted with C, and arbitrary A may be substituted with D,
but also means that a plurality of A may be substituted with at
least two of B-D. For example, the alkyl in which arbitrary
--CH.sub.2-- may be substituted with --O-- or --CH.dbd.CH--
includes alkyl, alkenyl, alkoxy, alkoxyalkyl, alkoxyalkenyl,
alkenyloxyalkyl, and the like. Furthermore, in the present
invention, the case in which two contiguous --CH.sub.2--are
substituted with --O-- to form --O--O-- is unsuitable, and the case
in which --CH.sub.2-terminal to an alkyl is substituted with --O--
is also unsuitable. The present invention will be further described
below. The terminal groups, rings, and bonding groups of the
compound of Formula (1) will also be illustrated with preferred
examples.
EFFECTS OF THE INVENTION
[0094] The liquid crystal compound of the present invention is
stable to heat and light, and has a large refractive index
anisotropy, a large dielectric anisotropy, and a low melting point.
Due to the low melting point, the content of the compound in the
liquid crystal composition may be high. The liquid crystal
composition is stable to heat and light, and includes a material of
an optically isotropic liquid crystal phase that exhibits a high
upper temperature and a low lower temperature, and has a low
driving voltage when used in a device driven in an optically
isotropic liquid crystal phase. The polymer/liquid crystal
composite material of the present invention contains a
polymer/liquid crystal composite material in an optically isotropic
liquid crystal phase, exhibits a high upper temperature and a low
lower temperature of the optically isotropic liquid crystal phase,
and has a low driving voltage when used in a device driven in an
optically isotropic liquid crystal phase.
The optical device driven in the optically isotropic liquid crystal
phase of the present invention can be used over a wide temperature
range, has a short response time, a large contrast, and a low
driving voltage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0095] The accompanying drawings are included to provide a further
understanding of the invention, and are incorporated in and
constitute a part of this specification. The drawings illustrate
embodiments of the invention and, together with the description,
serve to explain the principles of the invention.
[0096] FIG. 1 shows a comb-like electrode substrate used in
Examples 6, 7, 11 and 14; and
[0097] FIG. 2 shows an optical system used in Examples 8, 9, 12,
and 15.
DESCRIPTION OF THE EMBODIMENTS
1-1 Compound (1)
[0098] The liquid crystal compound of the present invention is the
compound of Formula (1). The liquid crystal composition having an
optically isotropic liquid crystal phase of the present invention
contains a compound of Formula (1) as Component A. A first aspect
of the liquid crystal composition of the present invention is a
composition of merely Component A or a composition of Component A
and other components not specifically indicated herein. First, the
compound of Formula (1) is described.
##STR00014##
[0099] In Formula (1), R.sup.1 is hydrogen or a C.sub.1-20 alkyl,
wherein arbitrary --CH.sub.2-- in the alkyl may be substituted with
--O--, --S--, --COO--, --OCO--, --CH.dbd.CH--, --CF.dbd.CF-- or
--C.ident.C--, and arbitrary hydrogen in the alkyl and in the group
formed by substituting arbitrary --CH.sub.2-- in the alkyl with
--O--, --S--, --COO--, --COO--, --CH.dbd.CH--, --CF.dbd.CF-- or
--C.ident.C-- may be substituted with halogen or a C.sub.1-3
alkyl.
[0100] For example, examples of the group formed by substituting
arbitrary --CH.sub.2-- in CH.sub.3(CH.sub.2).sub.3-- with --O--,
--S-- or --CH.dbd.CH-- are CH.sub.3(CH.sub.2).sub.2O--,
CH.sub.3--O--(CH.sub.2).sub.2--, CH.sub.3--O--CH.sub.2--O--,
CH.sub.3(CH.sub.2).sub.2S--, CH.sub.3--S--(CH.sub.2).sub.2--,
CH.sub.3--S--CH.sub.2--S--, CH.sub.2.dbd.CH--(CH.sub.2).sub.3--,
CH.sub.3--CH.dbd.CH--(CH.sub.2).sub.2--,
CH.sub.3--CH.dbd.CH--CH.sub.2O--, CH.sub.3CH.sub.2C.ident.C--, and
the like. For example, examples of the group formed by substituting
arbitrary hydrogen with halogen in CH.sub.3(CH.sub.2).sub.3-- or a
group formed by substituting arbitrary --CH.sub.2-- in
CH.sub.3(CH.sub.2).sub.3-- with --O--, --C.ident.C--, or
--CH.dbd.CH--, are ClCH.sub.2(CH.sub.2).sub.3--,
CF.sub.2.dbd.CH--(CH.sub.2).sub.3--, CH.sub.2F(CH.sub.2).sub.2O--,
CH.sub.2FCH.sub.2C.ident.C--.
[0101] A preferred stereo configuration of --CH.dbd.CH-- in alkenyl
depends on the position of the double bond. A trans-configuration
is preferred for such an alkenyl having a double bond at an odd
position, such as --CH.dbd.CHCH.sub.3, --CH.dbd.CHC.sub.2H.sub.5,
--CH.dbd.CHC.sub.3H.sub.7, --CH.dbd.CHC.sub.4H.sub.9,
--C.sub.2H.sub.4CH_.dbd.CHCH.sub.3, and
--C.sub.2H.sub.4CH.dbd.CHC.sub.2H.sub.5. A cis-configuration is
preferred for such an alkenyl having a double bond at an even
position, such as --CH.sub.2CH.dbd.CHCH.sub.3,
--CH.sub.2CH.dbd.CHC.sub.2H.sub.5, and
--CH.sub.2CH.dbd.CHC.sub.3H.sub.7. An alkenyl compound having a
preferred stereo configuration has a liquid crystal phase with a
high upper-limit temperature or over a wide temperature range,
which is illustrated in detail in Mol. Cryst. Liq. Cryst., 1985,
131, 109; and Mol. Cryst. Liq. Cryst., 1985, 131, 327. Moreover,
the position of the alkenyl is preferably that is not conjugated to
a benzyl ring.
[0102] The alkyl may be linear or branched, and specific examples
include --CH.sub.3, --C.sub.2H.sub.5, --C.sub.3H.sub.7,
--C.sub.4H.sub.9, --C.sub.5H.sub.11, --C.sub.6H.sub.13,
--C.sub.7H.sub.15, --C.sub.8H.sub.17, --C.sub.9H.sub.19,
--C.sub.10H.sub.21, --C.sub.11H.sub.23, --C.sub.12H.sub.25,
--C.sub.13H.sub.27, --C.sub.14H.sub.29 and --C.sub.15H.sub.31.
[0103] The alkoxy may be linear or branched, and specific examples
include --OCH.sub.3, --OC.sub.2H.sub.5, --OC.sub.3H.sub.7,
--OC.sub.4H.sub.9, --OC.sub.5H.sub.11, --OC.sub.6H.sub.13 and
--OC.sub.7H.sub.15, --OC.sub.8H.sub.17, --OC.sub.9H.sub.19,
--OC.sub.10H.sub.21, --OC.sub.11H.sub.23, --OC.sub.12H.sub.25,
--OC.sub.13H.sub.27 and --OC.sub.14H.sub.29.
[0104] The alkoxyalkyl may be linear or branched, and specific
examples include --CH.sub.2OCH.sub.3, --CH.sub.2OC.sub.2H.sub.5,
--CH.sub.2OC.sub.3H.sub.7, --(CH.sub.2).sub.2--OCH.sub.3,
--(CH.sub.2).sub.2--OC.sub.2H.sub.5,
--(CH.sub.2).sub.2--OC.sub.3H.sub.7, --(CH.sub.2).sub.3--OCH.sub.3,
--(CH.sub.2).sub.4--OCH.sub.3 and
--(CH.sub.2).sub.5--OCH.sub.3.
[0105] The alkenyl may be linear or branched, and specific examples
include --CH.sub.2CH.dbd.CH.sub.2, --CH.sub.2CH.dbd.CHCH.sub.3,
--(CH.sub.2).sub.2--CH.dbd.CH.sub.2,
--CH.sub.2CH.dbd.CHC.sub.2H.sub.5,
--(CH.sub.2).sub.2--CH.dbd.CHCH.sub.3 and
--(CH.sub.2).sub.3--CH.dbd.CH.sub.2.
[0106] The alkenyloxy may be linear or branched, and specific
examples include --OCH.sub.2CH.dbd.CH.sub.2,
--OCH.sub.2CH.dbd.CHCH.sub.3 and
--OCH.sub.2CH.dbd.CHC.sub.2H.sub.5.
[0107] The alkynyl may be linear or branched, and specific examples
include --C.ident.CH, --C.ident.CCH.sub.3, --CH.sub.2C.ident.CH,
--C.ident.CC.sub.2H.sub.5, --CH.sub.2C.dbd.CCH.sub.3,
--(CH.sub.2).sub.2--C.ident.CH, --C.ident.CC.sub.3H.sub.7,
--CH.sub.2C.ident.CC.sub.2H.sub.5,
--(CH.sub.2).sub.2--C.ident.CCH.sub.3 and
--C.ident.C(CH.sub.2).sub.s.
[0108] R.sup.1 preferably has a structure as shown in Formulas
(CHN-1) to (CHN-6).
[0109] Herein, R.sup.1a is hydrogen or a C.sub.1-20 alkyl, and more
preferably (CHN-1) or (CHN-2).
##STR00015##
[0110] In Formula (1), Z.sup.1, Z.sup.2, Z.sup.3, Z.sup.4, Z.sup.5
and Z.sup.6 are independently a single bond or --CF.sub.2O--,
provided that at least one of Z.sup.1, Z.sup.2, Z.sup.3, Z.sup.4,
Z.sup.5 and Z.sup.6 is --CF.sub.2O--, and more preferably only one
of Z.sup.1, Z.sup.2, Z.sup.3, Z.sup.4, Z.sup.5 and Z.sup.6 is
--CF.sub.2O--.
[0111] In Formula (1), L.sup.1, L.sup.2, L.sup.3, L.sup.4 and
L.sup.5 are independently hydrogen or fluorine. In case that
L.sup.1 is hydrogen, Compound (1) has a low melting point and
excellent compatibility with other liquid crystal compounds; and in
case that L.sup.1 is fluorine, Compound (1) exhibits a large
dielectric anisotropy.
[0112] In Formula (1), X.sup.1 is halogen, --C.ident.N,
--N.dbd.C.dbd.S, --SF.sub.5, or a C.sub.1-3 alkyl, in which
arbitrary hydrogen is substituted with fluorine, and arbitrary
--CH.sub.2-- may be substituted with --O--, --S--, --CH.dbd.CH-- or
--C.dbd.C--.
[0113] Specific examples of alkyl in which arbitrary hydrogen is
substituted with fluorine are --CHF.sub.2, --CF.sub.3,
--CF.sub.2CH.sub.2F, --CF.sub.2CHF.sub.2, --CH.sub.2CF.sub.3,
--CF.sub.2CF.sub.3, --(CH.sub.2).sub.3--F, --(CF.sub.2).sub.3--F,
--CF.sub.2CHFCF.sub.3, --CHFCF.sub.2CF.sub.3, --(CF.sub.2).sub.4--F
and --(CF.sub.2).sub.5--F.
[0114] Specific examples of alkoxy in which arbitrary hydrogen is
substituted with fluorine are --OCHF.sub.2, --OCF.sub.3,
--OCF.sub.2CH.sub.2F, --OCF.sub.2CHF.sub.2, --OCH.sub.2CF.sub.3,
--O--(CF.sub.2).sub.3--F, --OCF.sub.2CHFCF.sub.3,
--OCHFCF.sub.2CF.sub.3, --O--(CF.sub.2).sub.4--F and
--O--(CF.sub.2).sub.5--F.
[0115] Specific examples of alkenyl in which arbitrary hydrogen is
substituted with fluorine are --CH.dbd.CF.sub.2, --CF.dbd.CHF,
--CH.dbd.CHCH.sub.2F, --CH.dbd.CHCF.sub.3,
--(CH.sub.2).sub.2--CH.dbd.CF.sub.2, --CH.sub.2CH.dbd.CHCF.sub.3
and --CH.dbd.CHCF.sub.2CF.sub.3.
[0116] Preferred specific examples of X.sup.1 are fluorine,
chlorine, --SF.sub.5, --CHF.sub.2, --CF.sub.3, --CF.sub.2CH.sub.2F,
--CF.sub.2CHF.sub.2, --CH.sub.2CF.sub.3, --CF.sub.2CF.sub.3,
--(CF.sub.2).sub.3--F, --CF.sub.2CHFCF.sub.3,
--CHFCF.sub.2CF.sub.3, --(CF.sub.2).sub.4--F,
--(CF.sub.2).sub.5--F, --OCHF.sub.2, --OCF.sub.3,
--OCF.sub.2CH.sub.2F, --OCF.sub.2CHF.sub.2, --OCH.sub.2CF.sub.3,
--O--(CF.sub.2).sub.3--F, --OCF.sub.2CHFCF.sub.3,
--OCHFCF.sub.2CF.sub.3, --O--(CF.sub.2).sub.4--F,
--O--(CF.sub.2).sub.5--F, --CH.dbd.CF.sub.2, --CF.dbd.CHF,
--CH.dbd.CHCF.sub.3, --(CH.sub.2).sub.2--CH.dbd.CF.sub.2,
--CH.sub.2CH.dbd.CHCF.sub.3 and --CH.dbd.CHCF.sub.2CF.sub.3.
[0117] More preferred examples of X.sup.1 are fluorine, chlorine,
--CF.sub.3, --CHF.sub.2, --OCF.sub.3 and --OCHF.sub.2. Most
preferred examples of X.sup.1 are fluorine, chlorine, --CF.sub.3
and --OCF.sub.3.
[0118] In Formula (1), l, m, n, o and p are independently 0 or 1,
and 1.ltoreq.+m+n+o+p.ltoreq.2.
[0119] Formula (1) preferably has a structure represented by
Formulas (1-1)-(1-6).
##STR00016##
[0120] In the Formulas, R.sup.1 is a C.sub.1-20 alkyl, a C.sub.2-21
alkenyl, a C.sub.2-21 alkynyl, a C.sub.1-19 alkoxy, a C.sub.2-20
alkenyloxy, a C.sub.1-19 alkylthio, a C.sub.2-19 alkenylthio, or
--(CH.sub.2).sub.v--CH.dbd.CF.sub.2, in which v is 0 or an integer
of 1-19; Z.sup.1, Z.sup.2, Z.sup.3, Z.sup.4, Z.sup.5 and Z.sup.6
are independently a single bond or --CF.sub.2O--, provided that at
least one of Z.sup.1, Z.sup.2, Z.sup.3, Z.sup.4, Z.sup.5 and
Z.sup.6 is --CF.sub.2O--; L.sup.1 L.sup.2, L.sup.3 L.sup.4 and
L.sup.5 are independently hydrogen or fluorine; X.sup.1 is halogen,
--SF.sub.5, --CH.sub.2F, --CHF.sub.2, --CF.sub.3,
--(CH.sub.2).sub.2--F, --CF.sub.2CH.sub.2F, --CF.sub.2CHF.sub.2,
--CH.sub.2CF.sub.3, --CF.sub.2CF.sub.3, --(CH.sub.2).sub.3--F,
--(CF.sub.2).sub.3--F, --CF.sub.2CHFCF.sub.3,
--CHFCF.sub.2CF.sub.3, --(CH.sub.2).sub.4--F,
--(CF.sub.2).sub.4--F, --(CH.sub.2).sub.5--F,
--(CF.sub.2).sub.5--F, --OCH.sub.2F, --OCHF.sub.2, --OCF.sub.3,
--O--(CH.sub.2).sub.2--F, --OCF.sub.2CH.sub.2F,
--OCF.sub.2CHF.sub.2, --OCH.sub.2CF.sub.3,
--O--(CH.sub.2).sub.3--F, --O--(CF.sub.2).sub.3--F,
--OCF.sub.2CHFCF.sub.3, --OCHFCF.sub.2CF.sub.3,
--O(CH.sub.2).sub.4--F, --O--(CF.sub.2).sub.4--F,
--O--(CH.sub.2).sub.5--F, --O--(CF.sub.2).sub.5--F, --CH.dbd.CHF,
--CH.dbd.CF.sub.2, --CF.dbd.CHF, --CH.dbd.CHCH.sub.2F,
--CH.dbd.CHCF.sub.3, --(CH.sub.2).sub.2--CH.dbd.CF.sub.2,
--CH.sub.2CH.dbd.CHCF.sub.3 or --CH.dbd.CHCF.sub.2CF.sub.3.
[0121] Among the compounds, a compound is more preferred in which
R.sup.1 has a structure represented by any one of Formulas (CHN-1)
to (CHN-6), R.sup.1a is hydrogen or a C.sub.1-20 alkyl; Z.sup.1,
Z.sup.2, Z.sup.3, Z.sup.4, Z.sup.5 and Z.sup.6 are independently a
single bond or --CF.sub.2O--, provided that at least one of
Z.sup.1, Z.sup.2, Z.sup.3, Z.sup.4, Z.sup.5 and Z.sup.6 is
--CF.sub.2O--; L.sup.2, L.sup.3, L.sup.4 and L.sup.5 are
independently hydrogen or fluorine; X.sup.1 is fluorine, chlorine,
--CF.sub.3, --CHF.sub.2, --OCF.sub.3, --OCHF.sub.2, --OCH.sub.2F or
--C.dbd.C--CF.sub.3.
[0122] Among the compounds of Formulas (1-1) to (1-6), further more
preferred are compounds represented by Formulas (1-1-1) to Formula
(1-1-3), (1-2-1) to (1-2-3), (1-3-1) to (1-3-3), (1-4-1) to
(1-4-3), (1-5-1) to (1-5-3), and (1-6-1) to (1-6-3). Among the
compounds, further more preferred are compounds represented by
Formulas (1-1-1), (1-1-2), (1-2-1), (1-2-2), (1-3-1), (1-3-2),
(1-4-2), (1-4-3), (1-5-3), and (1-6-2).
##STR00017## ##STR00018##
[0123] In the Formulas, R.sup.1, L.sup.1, L.sup.5 and X.sup.1 have
the same meaning as defined for Formulas (1-1) to (1-6).
1-2 Properties of Compound (1)
[0124] Compound (1) used in the present invention is further
described in detail. Compound (1) is a liquid crystal compound
bearing a chlorophenyl ring, which has very stable physical and
chemical properties under the conditions where the device is
generally used, has an excellent compatibility with other liquid
crystal compounds, and is difficult to exhibit a smectic phase. The
composition containing such a compound is stable under the
conditions where the device is generally used. Therefore, the
composition has an optically isotropic liquid crystal phase in an
expanded temperature range, and thus can be used in a display
device over a wide temperature range. Moreover, due to large
dielectric anisotropy and refractive index anisotropy, the compound
can be used as a component for lowering the driving voltage in a
composition driven in an optically isotropic liquid crystal
phase.
[0125] By properly selecting the combination of l, m, n, o and p,
the left terminal group R.sup.1, the most right substituents on the
phenyl ring and substitution positions thereof (L.sup.1, L.sup.2
and X.sup.1), or the bonding groups Z.sup.1 to Z.sup.6 of the
Compound (1), the physical properties such as the clear point, the
refractive index anisotropy, and the dielectric anisotropy can be
adjusted at will. The effects of the combination of 1, m, n, o and
p, the left terminal group R.sup.1, the right terminal group
X.sup.1, and the bonding groups Z.sup.1 to Z.sup.6, and L.sup.1 to
L.sup.5 on the physical properties of the Compound (1) will be
described below.
[0126] Generally, when 1+m+n+o+p=2, the clear point of the
compounds is high, and when 1+m+n+o+p=1, the melting point of the
compounds is low.
[0127] When R.sup.1 is linear, Compound (1) has a liquid crystal
phase over a wide temperature range and a low viscosity. When
R.sup.1 is branched, Compound (1) is well compatible with other
liquid crystal compounds. The compound in which R.sup.1 is an
optically active group can be used as a chiral dopant. The compound
in which R.sup.1 is a non-optically active group can be used as a
component of the composition. When R.sup.1 is an alkenyl, a
preferred stereo configuration depends on the position of the
double bond. An alkenyl compound having a preferred stereo
configuration has a high upper-limit temperature or a liquid
crystal phase over a wide temperature range.
[0128] When the bonding groups Z.sup.1-Z.sup.6 are a single bond or
--CF.sub.2O--, Compound (1) has relatively stable chemical
properties and thus is unlikely to be deteriorated. Furthermore,
when the bonding group is a single bond, the Compound (1) has a low
viscosity. Moreover, where the bonding group is --CF.sub.2O--, the
Compound (1) exhibits a large dielectric anisotropy.
[0129] When the right terminal group X.sup.1 is fluorine, chlorine,
--SF.sub.5, --CF.sub.3, --OCF.sub.3 or --CH.dbd.CH--CF.sub.3,
Compound (1) has a large dielectric anisotropy. When X.sup.1 is
fluorine, --OCF.sub.3 or --CF3, Compound (1) has stable chemical
properties.
[0130] When L.sup.1 is hydrogen, Compound (1) has a low melting
point; when L.sup.1 is fluorine, Compound (1) has a large
dielectric anisotropy. When L.sup.4 and L.sup.5 are both fluorine,
Compound (1) has a very large dielectric anisotropy.
[0131] As described above, a compound with target physical
properties can be obtained by properly selecting the structure of
the rings and the types of the terminal groups, the bonding groups
and the like.
1-3 Specific Examples of Compound (1)
[0132] Preferred examples of Compound (1) are Formulas (1-1)-(1-6).
More preferred examples are Formulas (1-1-1)-(1-1-3),
(1-2-1)-(1-2-3), (1-3-1)-(1-3-3), (1-4-1)-(1-4-3), (1-5-1)-(1-5-3),
(1-6-1)-(1-6-3). Among the formulas, further more preferred are
Formulas (1-1-1), (1-1-2), (1-2-1), (1-2-2), (1-3-1), (1-3-2),
(1-4-2), (1-4-3), (1-5-3), and (1-6-2). Specific compounds include
compounds represented by Formulas (1-1-1-a)-(1-1-14),
(1-1-2-a)-(1-1-24), (1-2-1-a)-(1-2-14), (1-2-2-a)-(1-2-2-f),
(1-3-1-a)-(1-3-1-d), (1-3-2-a)-(1-3-2-d), (1-4-2-a)-(1-4-2-f),
(1-4-3-a)-(1-4-3-f), (1-5-3-a)-(1-5-3-f), and (1-6-2-a)-(1-6-2-c),
and the compounds represented by Formulas (S1-11), (S2-1), (S3-1),
(S4-1), (S5-1), (S6-1), (S7-1), Formula (S8-1), (S9-1), (S10-1),
and (S11-1) described in Examples 1-11.
##STR00019## ##STR00020## ##STR00021## ##STR00022## ##STR00023##
##STR00024## ##STR00025## ##STR00026## ##STR00027##
1-4 Synthesis of Compound (1)
[0133] Next, synthesis of Compound (1) is described. Compound (1)
may be synthesized by a suitable combination of organic synthesis
methods. The methods for introducing target terminal groups, rings,
and bonding groups in the starting material are described in, for
example, Organic Syntheses, John Wiley & Sons, Inc, Organic
Reactions, John Wiley & Sons, Inc, Comprehensive Organic
Synthesis, Pergamon Press, and New Lecture on Experimental
Chemistry (Maruzen).
1-4-1 Chlorophenyl Ring
[0134] Chlorobenzene compounds such as
1-bromo-3-chloro-5-fluorobenzene and 3-chloro-5-fluorophenol are
commercially available as reagent.
1-4-2 Formation of Bonding Groups Z.sup.1-Z.sup.6
[0135] An example for forming the bonding groups Z.sup.1-Z.sup.6 in
Compound (1) is as shown in the scheme below. In this scheme,
MSG.sup.1 or MSG.sup.2 is a monovalent organic group having at
least one ring. The multiple MSG.sup.1 (or MSG.sup.2) used in the
scheme can be the same or different. Compounds (1A)-(1J) are
equivalent to Compound (1).
##STR00028##
[0136] Next, the methods for forming each bond of the bonding
groups Z.sup.1-Z.sup.6 in Compound (1) are described in Sections
(I)-(II) below.
[0137] (I) Formation of Single Bond
[0138] Arylboric acid (20) is reacted with Compound (21), which is
synthesized by a well-known method, in the presence of an aqueous
carbonate solution and a catalyst such as
tetrakis(triphenylphosphine)palladium, to synthesize Compound (1A).
Compound (1A) may also be synthesized by reacting Compound (22)
synthesized by a well-known method through reacting with n-butyl
lithium, then reacting with zinc chloride, and next reacting with
Compound (21) in the presence of a catalyst such as
bis(triphenylphosphine)palladium dichloride.
[0139] (II) Formation of --CF.sub.2O--Compound (22) is reacted with
n-butyl lithium, and then reacted with carbon dioxide to produce
carboxylic acid (23). Next, Compound (23) and a phenol compound
(25) synthesized by a well-known method are subjected to
dehydration in the presence of DCC (1,3-dicyclohexylcarbodiimide)
and DMAP (4-dimethylaminopyridine) to synthesize Compound (24)
having --COO--. A compound having --COO-- may also be synthesized
by this method. Compound (24) is treated with a vulcanizing agent
such as Lawesson's reagent to produce Compound (26). Then, Compound
(26) is fluorinated with a hydrogen fluoride pyridine complex and
NBS (N-bromosuccinimide), to synthesize Compound (1B) having
--CF.sub.2O--. See M. Kuroboshi et al., Chem. Lett., 1992, 827.
Compound (1B) may also be synthesized by fluorinating Compound (26)
with (diethylamino)sulfur trifluoride (DAST). See W. H. Bunnelle et
al., J. Org. Chem. 1990, 55, 768. A compound having --OCF.sub.2--
may also be synthesized by this method. The bonding groups may also
be synthesized by the method described in Peer. Kirsch et al.,
Angew. Chem. Int. Ed. 2001, 40, 1480.
1-4-4 Synthesis of Compound (1)
[0140] There are numerous methods for synthesizing the compound of
Formula (1), and the compound of Formula (1) may be synthesized
from commercially available reagents with proper reference to the
examples in the specification or documents and books.
[0141] 2 Compounds (2)-(11)
[0142] A second aspect of the present invention relates to a liquid
crystal composition obtained by adding a component selected from
the components B, C, D, and E shown below to the compound of
Formula (1) (i.e. Component A). Compared with a composition merely
containing Component A, the liquid crystal composition can be
freely adjusted for the driving voltage, temperature range of a
liquid crystal phase, refractive index anisotropy value, dielectric
anisotropy value, viscosity and so on.
[0143] Preferably, the component to be added into the component A
is a mixture obtained by mixing Component B, C, D, E, or F, where
Component B includes at least one compound selected from the group
consisting of Formulas (2), (3), and (4) above, Component C
includes at least one compound selected from the group consisting
of Formula (5) above, Component D includes at least one compound
selected from the group consisting of Formula (6) above, Component
E includes at least one compound selected from the group consisting
of Formulas (7)-(10) above, and Component F includes at least one
compound selected from the group consisting of Formula (11)
above.
[0144] Moreover, for each component of the liquid crystal
composition used in the present invention, an analogue containing
isotopes of each element can be used due to the small difference in
physical properties.
[0145] In Component B above, preferred examples for the compound of
Formula (2) are Formulas (2-1) to (2-16), preferred examples for
the compound of Formula (3) are Formulas (3-1) to (3-112), and
preferred examples for the compound of Formula (4) are Formulas
(4-1) to (4-52).
##STR00029## ##STR00030## ##STR00031## ##STR00032## ##STR00033##
##STR00034## ##STR00035## ##STR00036## ##STR00037## ##STR00038##
##STR00039## ##STR00040## ##STR00041## ##STR00042## ##STR00043##
##STR00044## ##STR00045## ##STR00046## ##STR00047## ##STR00048##
##STR00049## ##STR00050## ##STR00051## ##STR00052##
(in these formulas, R.sup.2 and X.sup.2 are defined as above.)
[0146] The compounds of the Formulas (2)-(4) (i.e. Component B)
have a positive dielectric anisotropy value and very good thermal
or chemical stability, and thus are useful for preparing a liquid
crystal composition for TFT. Based on the total weight of the
liquid crystal composition, the content of Component B in the
liquid crystal composition of the present invention is suitably
1-99 wt %, preferably 10-97 wt %, and more preferably 40-95 wt
%.
[0147] Preferred examples for the compound of Formula (5) (i.e.
Component C) are Formulas (5-1) to (5-62).
##STR00053## ##STR00054## ##STR00055## ##STR00056## ##STR00057##
##STR00058## ##STR00059##
[0148] (in the formulas, R.sup.3 and X.sup.3 are defined as
above.)
[0149] The compounds of the Formulas (5) (i.e. Component C) has a
positive and very large dielectric anisotropy value. The driving
voltage of the composition can be lowered, when the liquid crystal
composition contains Component C. Moreover, the viscosity and the
refractive index anisotropy value can be adjusted, and the
temperature range of a liquid crystal phase can be expanded.
[0150] Based on the total weight of the composition, the content of
Component C is preferably 0.1-99.9 wt %, more preferably 10-97 wt
%, and still more preferably 40-95 wt %. Furthermore, the threshold
voltage, the liquid crystal phase temperature range, the refractive
index anisotropy value, the dielectric anisotropy value, and the
viscosity can be adjusted by mixing with the components below.
[0151] Preferred examples for the compound of Formula (6)
(Component D) are Formulas (6-1)-(6-6).
##STR00060##
[0152] (in the formulas, R.sup.4 and R.sup.5 are defined as
above.)
[0153] The compounds of Formula (6) (Component D) have a small
absolute value of dielectric anisotropy, and are nearly neutral.
The compounds of Formula (6) have the effect of expanding the
temperature range of an optically isotropic liquid crystal phase,
such as increasing the clear point, or have the effect of adjusting
the refractive index anisotropy value.
[0154] If the content of the compounds of Component D is increased,
the driving voltage of the liquid crystal composition is raised,
and the viscosity is lowered. Therefore, the content of the
compounds of Component D is expected to be as high as possible,
provided that the desired driving voltage of the liquid crystal
composition can be met. During the preparation of a liquid crystal
composition for TFT, the content of Component D is preferably 60 wt
% or less, and more preferably 40 wt % or less, based on the total
weight of the composition.
[0155] In order for the liquid crystal composition of the present
invention to exhibit excellent properties, it is preferred that the
liquid crystal composition contains 0.1-99 wt % of at least one
compound of Formula (1) of the present invention.
[0156] The liquid crystal composition of the present invention
generally can be prepared by a well-know method, for example, a
method in which essential components are dissolved at high
temperature.
[0157] 3 Compounds (7)-(11)
[0158] A third aspect of the present invention is a liquid crystal
composition obtained by adding a component selected from Components
E and F below to Component A.
[0159] Preferably, a component added to Component A is a mixture
obtained by mixing Component E or F, where Component E includes at
least one compound selected from the group consisting of Formulas
(7), (8), (9), and (10) above, and Component F includes at least
one compound selected from the group consisting of Formula (11)
above.
[0160] Moreover, for each component of the liquid crystal
composition used in the present invention, an analogue containing
isotopes of each element also can be used due to the small
difference in physical properties.
[0161] In Component E above, preferred examples for the compound of
Formula (7) are Formulas (7-1) to (7-8), preferred examples for the
compound of Formula (8) are Formulas (8-1) to (8-26), preferred
examples for the compound of Formula (9) are Formulas (9-1) to
(9-22), and preferred examples for the compound of Formula (10) are
Formulas (10-1) to (10-5).
##STR00061## ##STR00062## ##STR00063## ##STR00064## ##STR00065##
##STR00066## ##STR00067## ##STR00068## ##STR00069##
[0162] (in the formulas, R.sup.6 and X.sup.4 are defined as above;
and (F) denotes hydrogen or fluorine, and (F, Cl) denotes hydrogen,
fluorine, or chlorine.)
[0163] The compounds of the Formulas (7)-(10) (i.e. Component E)
have a positive and very large dielectric anisotropy value and very
good thermal and chemical stability, and thus are suitable for
preparing a liquid crystal composition used in active driving such
as TFT driving. In the liquid crystal composition of the present
invention, the content of Component E is suitably in the range of
1-99 wt %, preferably 10-97 wt %, and more preferably 40-95 wt %,
based on total weight of the liquid crystal composition.
Furthermore, the clear point and viscosity can be adjusted, when
the liquid crystal composition further contains the compounds of
Formula (6) (Component D).
[0164] Preferred examples for the compound of Formula (11) above
(i.e. Component F) are Formulas (11-1) to (11-37).
##STR00070## ##STR00071## ##STR00072## ##STR00073##
##STR00074##
[0165] (in the formulas, R.sup.7, X.sup.5, (F), and (F, Cl) are
defined as above.)
[0166] These compounds of Formula (11) (i.e. Component F) have a
positive and very large dielectric anisotropy value, and thus are
mainly used to lower the driving voltage of the devices below:
devices driven in an optically isotropic liquid crystal phase,
polymer dispersed LCD (PDLCD) devices, polymer network LCD (PNLCD)
devices, polymer-stabilized cholesteric LCD (PSCLCD) devices, and
so on. When the liquid crystal composition contains Component F,
the driving voltage of the composition can be lowered, as well as
the viscosity and the refractive index anisotropy value may also be
adjusted, and the temperature range of a liquid crystal phase can
be expanded. Moreover, Component F may also be used to improve the
sharpness.
[0167] The content of Component F is preferably in the range of
0.1-99.9 wt %, more preferably 10-97 wt %, and still more
preferably 40-95 wt %, based on the total weight of the
composition.
[0168] 4 Composition Having Optically Isotropic Liquid Crystal
Phase
[0169] 4.1 Composition of Composition Having Optically Isotropic
Liquid Crystal Phase
[0170] A fourth aspect of the present invention is a composition
containing the compound of Formula (1) and a chiral reagent, which
is a liquid crystal composition useful in an optical device driven
in an optically isotropic liquid crystal phase and exhibiting an
optically isotropic liquid crystal phase.
[0171] The compound of Formula (1) has a low clear point, a large
dielectric anisotropy, and a large refractive index anisotropy, and
the content of the compound of Formula (1) may be 5-100 wt %,
preferably 5-80 wt %, and more preferably 10-70 wt %, based on the
total weight of the non-chiral liquid crystal composition without a
chiral reagent.
[0172] The content of the chiral reagent is preferably 1-40 wt %,
more preferably 3-25 wt %, and most preferably 5-15 wt %, based on
the total weight of the liquid crystal composition. A liquid
crystal composition in which the content of the chiral reagent is
the range above is likely to have an optically isotropic liquid
crystal phase, and thus is preferred.
[0173] The chiral reagent contained in the liquid crystal
composition may be a single reagent, or a mixture of two or more
reagents.
[0174] 4.2 Chiral Reagent
[0175] The chiral reagent contained in the optically isotropic
liquid crystal composition is preferably a compound with a large
helical twisting power. When a compound with a large helical
twisting power is used, the addition amount required for obtaining
a desired pitch is reduced, thus preventing the driving voltage
from being raised, which is advantageous in practice. Specifically,
the compounds of Formulas (K1)-(K5) below are preferred.
##STR00075##
[0176] In Formulas (K1)-(K5), R.sup.K is independently hydrogen,
halogen, --C.ident.N, --N.dbd.C.dbd.O, --N.dbd.C.dbd.S or a
C.sub.1-20 alkyl, wherein arbitrary --CH.sub.2-- in the alkyl may
be substituted with --O--, --S--, --COO--, --OCO--, --CH.dbd.CH--,
--CF.dbd.CF-- or --C.ident.C--, and arbitrary hydrogen in the alkyl
may be substituted with halogen; A is independently an aromatic or
non-aromatic 3 to 8-membered ring, or a fused ring of 9 or more
carbons, wherein arbitrary hydrogen in the rings may be substituted
with halogen, a C.sub.1-3 alkyl or a C.sub.1-3 haloalkyl,
--CH.sub.2-- in the rings may be substituted with --O--, --S-- or
--NH--, and --CH.dbd. in the rings may be substituted with
--N.dbd.; B is independently hydrogen, halogen, a C.sub.1-3 alkyl,
a C.sub.1-3 haloalkyl, an aromatic or non-aromatic 3 to 8-membered
ring, or a fused ring of 9 or more carbons, wherein arbitrary
hydrogen in the rings may be substituted with halogen, a C.sub.1-3
alkyl or a C.sub.1-3 haloalkyl, --CH.sub.2-- in the rings may be
substituted with --O--, --S-- or --NH--, and --CH.dbd. in the rings
may be substituted with --N.dbd.; Z is independently a single bond,
or a C.sub.1-8 alkylene, in which arbitrary --CH.sub.2-- in the
alkylene may be substituted with --O--, --S--, --COO--, --OCO--,
--CSO--, --OCS--, --N.dbd.N--, --CH.dbd.N--, --N.dbd.CH--,
--CH.dbd.CH--, --CF.dbd.CF-- or --C.ident.C--, and arbitrary
hydrogen in the alkylene may be substituted with halogen; X is a
single bond, --COO--, --OCO--, --CH.sub.2O--, --OCH.sub.2--,
--CF.sub.2O--, --OCF.sub.2--, or --CH.sub.2CH.sub.2--; and mK is
1-4.
[0177] Among these compounds, the chiral reagent added in the
liquid crystal composition is preferably Formulas (K2-1)-(K2-8)
covered by Formula (K2), Formulas (K4-1)-(K4-6) covered by Formula
(K4), and Formulas (K5-1)-(K5-3) covered by Formula (K5).
##STR00076## ##STR00077## ##STR00078##
[0178] (in the formulas, R.sup.K(is independently a C.sub.3-10
alkyl, wherein --CH.sub.2-- adjacent to a ring in the alkyl may be
substituted with --O--, and arbitrary --CH.sub.2-- in the alkyl may
be substituted with --CH.dbd.CH--.)
[0179] 4.3 Optically Isotropic Liquid Crystal Phase
[0180] The so-called liquid crystal composition having optical
isotropy means that the composition exhibits optical isotropy
because the arrangement of liquid crystal molecules is
macroscopically isotropic, but has microscopic liquid crystal
order. "Pitch corresponding to the microscopic liquid crystal order
of the liquid crystal composition (sometimes referred to as pitch,
hereinafter)" is preferably 700 nm or less, more preferably 500 nm
or less, and most preferably 350 nm or less.
[0181] Herein, the so-called "non-liquid crystal isotropic phase"
refers to a commonly defined isotropic phase (i.e. disordered
phase), that is, a phase that still exhibits isotropy due to
fluctuation, even when a region with a non-zero local order
parameter is generated. For example, an isotropic phase exhibited
at a high temperature side of a nematic phase is equivalent to the
non-liquid crystal isotropic phase in this specification. The
chiral liquid crystal in this specification also is similarly
defined. Moreover, the so-called "optically isotropic liquid
crystal phase" in this specification means a phase that exhibits
optical isotropy without fluctuation, an example of which is a
phase having platelet tissue (i.e. blue phase in narrow sense).
[0182] The optically isotropic liquid crystal composition of the
present invention has an optically isotropic liquid crystal phase.
However, the typical platelet tissue is not observed in the blue
phase under a polarizing microscope sometimes. Therefore, in this
specification, a phase exhibiting the platelet tissue is designated
as blue phase, and an optically isotropic liquid crystal phase
including the blue phase is designated as optically isotropic
liquid crystal phase. That is, the blue phase is included in the
optically isotropic liquid crystal phase.
[0183] Generally, the blue phase can be classified into three
types, the blue phase I, the blue phase II, and the blue phase III,
and all the three types of blue phases are optical active and
isotropic. In the blue phase I or the blue phase II, two or more
types of diffracted light produced by the Bragg reflection from
different lattice planes are observed. The blue phase is generally
observed between the non-liquid crystal isotropic phase and the
chiral nematic phase.
[0184] That the optically isotropic liquid crystal phase does not
exhibit two or more colors of diffracted light means that a
platelet tissue observed in the blue phase I, blue phase II is not
observed and the phase exhibits substantially a single color in the
entire plane. For an optically isotropic liquid crystal phase not
exhibiting two or more colors of diffracted light,
brightness/darkness of the colors is not necessarily to be even in
plane.
[0185] The optically isotropic liquid crystal phase not exhibiting
two or more colors of diffracted light has the advantage of
inhibiting the intensity of reflected light caused by Bragg
reflection, or shifting toward the low wavelength side.
[0186] Furthermore, when a liquid crystal material reflecting
visible light is used in a display device, sometimes a color
variation problem may occur. However, for a liquid crystal not
exhibiting two or more colors of diffracted light, the reflection
of visible light may be eliminated in the helical pitch larger than
that in the blue phase in narrow sense (a phase exhibiting the
platelet tissue), as a result of reflection wavelength shift toward
the low wavelength side.
[0187] The optically isotropic liquid crystal composition of the
present invention can be obtained by adding a chiral reagent to a
composition having a nematic phase. In this case, the chiral
reagent is preferably added in a concentration such that the
helical pitch is 700 nm or less. Furthermore, the composition
having a nematic phase contains the compound of Formula (1) and
other optional components. Moreover, the optically isotropic liquid
crystal composition of the present invention may also be obtained
by adding a chiral reagent to a composition having a chiral nematic
phase but no optically isotropic liquid crystal phase. Furthermore,
the composition having a chiral nematic phase but no optically
isotropic liquid phase contains the compound of Formula (1), an
optically active compound, and other optional components. In this
case, the optically active compound is preferably added in a
concentration such that the helical pitch is 700 nm or more, so as
not to exhibit an optically isotropic liquid crystal phase. Herein,
the optically active compounds added may be the compounds with a
large helical twisting power, that is, the compounds of Formulas
(K1)-(K5), (K2-1)-(K2-8), Formulas (K4-1)-(K4-6), or Formulas
(K5-1)-(K5-3). Moreover, the optically active compound added may
not have a so large helical twisting power. Such an optically
active compound is, for example, one added in a liquid crystal
composition for a device driven in a nematic phase (for example,
the TN mode and the STN mode).
[0188] Examples of the optically active compound without a so large
helical twisting power are the following optically active Compounds
(Op-1)-(Op-13).
##STR00079## ##STR00080##
[0189] Moreover, the temperature range of the optically isotropic
liquid crystal composition of the present invention may be expanded
by adding a chiral reagent to a liquid crystal composition having
the co-existence of a nematic phase or a chiral nematic phase and
an non-liquid crystal isotropic phase over a wide temperature range
for exhibiting an optically isotropic liquid crystal phase. For
example, a composition exhibiting an optically isotropic liquid
crystal phase in a wide temperature range can be prepared as
follows. A liquid crystal compound having a high clear point is
mixed with a liquid crystal compound having a low clear point, to
prepare a liquid crystal composition with a wide temperature range
of the co-existence of a nematic phase and an isotropic phase.
Then, a chiral reagent is added to the liquid crystal
composition.
[0190] For a liquid crystal composition with a wide coexisting
temperature range of a nematic phase or chiral nematic phase and a
non-liquid crystal isotropic phase, the difference between the
upper-limit temperature and lower-limit temperature of the
co-existence is preferably 3-150.degree. C., and more preferably
5-150.degree. C. Moreover, for a preferred liquid crystal
composition, the difference between the upper-limit temperature and
lower-limit temperature of the co-existence of the nematic phase
and the non-liquid crystal isotropic phase is 3-150.degree. C.
[0191] When an electric field is applied to the liquid crystal
medium of the present invention in an optically isotropic liquid
crystal phase, an electrically controlled birefringence occurs, but
the Kerr effect does not necessarily occur.
[0192] Because the electrically controlled birefringence effect of
an optically isotropic liquid crystal phase increases with the
helical pitch, the electrically controlled birefringence effect can
be improved by adjusting the kind and content of the chiral reagent
to increase the helical pitch, provided that other optical
properties, such as, transmittance and diffraction wavelength,
could be satisfied.
[0193] 4.4 Other Components
[0194] Other compounds, such as polymer material, may be further
added into the optically isotropic liquid crystal composition of
the present invention, so long as they do not affect the properties
of the composition. In addition to the polymer material, the liquid
crystal composition of the present invention can also contain, for
example, a dichroic dye or a photochromic compound. Examples of the
dichroic dye include merocyanine dyes, styryl dyes, azo dyes,
azomethine dyes, azoxy dyes, quinophthalone dyes, anthraquinone
dyes, tetrazine dyes, and so on.
[0195] 5. Optically Isotropic Polymer/Liquid Crystal Composite
Material
[0196] A fifth aspect of the present invention is a composite
material of a polymer and a liquid crystal composition containing
the compound of Formula (1) and a chiral reagent, which exhibits an
optical isotropy. The composite material is an optically isotropic
polymer/liquid crystal composite material which can be used in an
optical device driven in an optically isotropic liquid crystal
phase. The optically isotropic polymer/liquid crystal composite
material contains a liquid crystal with polymer-stabilized blue
phase of Non-patent Document 1, obtained by polymerizing a mixture
of a monomer and a liquid crystal in blue phase, or a
quasi-isotropic liquid crystal of Non-patent Document 2, obtained
by polymerizing a mixture of a monomer and a liquid crystal in
isotropic phase. Such a polymer/liquid crystal composite material
includes, for example, the liquid crystal composition according to
items 1-30 (liquid crystal composition CLC) and a polymer.
[0197] The "polymer/liquid crystal composite material" of the
present invention has no particular limitation, provided that it is
a composite containing a liquid crystal material and a polymer
compound, where the polymer compound may be partially or entirely
not dissolved in the liquid crystal material, such that the polymer
compound is separated from the liquid crystal material.
Furthermore, in this specification, a nematic phase refers to one
in narrow sense but does not include a chiral nematic phase, unless
specifically indicated.
[0198] The optically isotropic polymer/liquid crystal composite
material according to a preferred aspect of the present invention
can exhibit an optically isotropic liquid crystal phase in a wide
temperature range. Moreover, the polymer/liquid crystal composite
material according to a preferred aspect of the present invention
has a very high response speed. Furthermore, based on such effects,
the polymer/liquid crystal composite material according to a
preferred aspect of the present invention is useful in an optical
device such as a display device.
[0199] 5.2 Polymer
[0200] Although the composite material of the present invention can
be produced by mixing an optically isotropic liquid crystal
composition with a pre-polymerized polymer, it is preferably
produced by mixing a low-molecular weight monomer, macromonomer, or
oligomer (generally referred to as "monomers", hereinafter) of the
polymer, with the liquid crystal composition CLC, and then
polymerizing the mixture. In this specification, the mixture
containing the monomers and the liquid crystal composition is
referred to as "polymerizable monomer/liquid crystal mixture". The
"polymerizable monomer/liquid crystal mixture" may optionally
contain a polymerization initiator, a curing agent, a catalyst, a
stabilizer, a dichroic dye, or a photochromic compound, and so on,
without compromising the effects of the present invention. For
example, the polymerizable monomer/liquid crystal mixture of the
present invention may also optionally contain 0.1-20 weight parts
of a polymerization initiator, based on 100 weight parts of the
polymerizable monomer.
[0201] The polymerization temperature is preferably such a
temperature that the polymer/liquid crystal composite material
exhibits a high transparency and isotropy, and more preferably such
a temperature that the mixture of the monomer and the liquid
crystal material exhibits an isotropic phase or a blue phase, while
the polymerization is terminated in the isotropic phase or
optically isotropic liquid crystal phase. That is, the temperature
is preferably set, such that after the polymerization, the
polymer/liquid crystal composite material substantially does not
scatter light of wavelength greater than that of visible light and
exhibits an optical isotropy.
[0202] For example, a low-molecular weight monomer, macromonomer,
and oligomer can be used as a raw material of the polymer forming
the composite material of the present invention. In this
specification, the so-called raw material monomer of the polymer
covers low-molecular weight monomer, macromonomer, oligomer, and so
on. Furthermore, the obtained polymer preferably has a
three-dimensional cross-linked structure, so the raw material
monomer of the polymer is preferably a multi-functional monomer
having two or more polymerizable functional groups. The
polymerizable functional groups have no particular limitation, and
include, for example, acryloyl, methacryloyl, glycidyl, epoxy,
oxetanyl, vinyl, and the like. In view of the polymerization rate,
acryloyl and methacryloyl are preferred. It is preferred that the
raw material monomer of the polymer contains 10 wt % or more of the
monomer having two or more polymerizable functional groups, since
the obtained composite material of the present invention can easily
exhibit a high transparency and isotropy.
[0203] Moreover, in order to obtain a suitable composite material,
the polymer preferably has a mesogen moiety, and a part or all of
the raw material monomers of the polymer may be the raw material
monomers having a mesogen moiety.
[0204] 5.2.1 Mono- and Difunctional Monomer Having Mesogen
Moiety
[0205] The mono- or difunctional monomer having a mesogen moiety
has no particular limitation in structure, and can be, for example,
the compounds of Formula (M1) or (M2) below.
##STR00081##
[0206] In Formula (M1), R.sup.a is each independently hydrogen,
halogen, --C.ident.N, --N.dbd.C.dbd.S, or a C.sub.1-20 alkyl, in
which arbitrary --CH.sub.2-- may be substituted with --O--, --S--,
--CO--, --COO--, --OCO--, --CH.dbd.CH--, --CF.dbd.CF-- or
--C.ident.C--, and arbitrary hydrogen may be substituted with
halogen or --C.ident.N. R.sup.b is each independently polymerizable
group of Formulas (M3-1)-(M3-7).
[0207] R.sup.a is preferably hydrogen, halogen, --C.ident.N,
--CF.sub.3, --CF.sub.2H, --CFH.sub.2, --OCF.sub.3, --OCF.sub.2H, a
C.sub.1-20 alkyl, a C.sub.1-19 alkoxy, a C.sub.2-21 alkenyl, and a
C.sub.2-21 alkynyl. Particularly preferably, R.sup.a is a
C.sub.1-20 alkyl and a C.sub.1-19 alkoxy.
[0208] In Formula (M2), R.sup.b is each independently a
polymerizable group of Formulas (M3-1)-(M3-7).
[0209] Herein, in Formulas (M3-1)-(M3-7), R.sup.d is each
independently hydrogen, halogen or a C.sub.1-5 alkyl, in which
arbitrary hydrogen may be substituted with halogen. R.sup.d is
preferably hydrogen, halogen and methyl. Most preferably, R.sup.d
is hydrogen, fluorine and methyl.
[0210] Furthermore, Formula (M3-2), Formula (M3-3), Formula (M3-4),
and Formula (M3-7) are suitably polymerized through free radical
polymerization. Formula (M3-1), Formula (M3-5), and Formula (M3-6)
are suitably polymerized through cationic polymerization. The
polymerizations above are living polymerizations, and are initiated
when a small amount of free radicals or cationic active species are
generated in the reaction system. In order to accelerate the
generation of the active species, a polymerization initiator may be
used. Light or heat may be used to generate active species.
[0211] In Formulas (M1) and (M2), A.sup.M is each independently an
aromatic or non-aromatic 5 or 6-membered ring, or a fused ring of 9
or more carbons, in which --CH.sub.2-- may be substituted with
--O--, --S--, --NH-- or --NCH.sub.3--, --CH.dbd. may be substituted
with --N.dbd., and hydrogen atoms may be substituted with halogen,
and a C.sub.1-5 alkyl or a C.sub.1-5 haloalkyl. Specific examples
of preferred A.sup.M are 1,4-cyclohexylene, 1,4-cyclohexenylene,
1,4-phenylene, naphthalene-2,6-diyl,
tetrahydronaphthalene-2,6-diyl, fluorene-2,7-diyl, or
bicyclo[2.2.2]octane-1,4-diyl, in which arbitrary --CH.sub.2-- may
be substituted with --O--, arbitrary --CH.dbd. may be substituted
with --N.dbd., and arbitrary hydrogen may be substituted with
halogen, a C.sub.1-5 alkyl or a C.sub.1-5 haloalkyl.
[0212] In consideration of the stability of the compound,
--CH.sub.2--O--CH.sub.2--O-- with oxygen being not adjacent to one
another is preferred to --CH.sub.2--O--O--CH.sub.2-- with oxygen
being adjacent to one another. The same case is applicable to
sulfur.
[0213] Among the groups, preferred A.sup.M is 1,4-cyclohexylene,
1,4-cyclohexenylene, 1,4-phenylene, 2-fluoro-1,4-phenylene,
2,3-difluoro-1,4-phenylene, 2,5-difluoro-1,4-phenylene,
2,6-difluoro-1,4-phenylene, 2-methyl-1,4-phenylene,
2-trifluoromethyl-1,4-phenylene,
2,3-bis(trifluoromethyl)-1,4-phenylene, naphthalene-2,6-diyl,
tetrahydronaphthalene-2,6-diyl, fluorene-2,7-diyl,
9-methylfluorene-2,7-diyl, 1,3-dioxane-2,5-diyl, pyridine-2,5-diyl,
and pyrimidine-2,5-diyl. Moreover, the stereo configuration of
1,4-cyclohexylene and 1,3-dioxane-2,5-diyl above is in
trans-configuration superior to in cis-configuration.
[0214] Because 2-fluoro-1,4-phenylene and 3-fluoro-1,4-phenylene
are identical in structure, the latter is not exemplified. This
rule is also applicable to the relationship between
2,5-difluoro-1,4-phenylene and 3,6-difluoro-1,4-phenylene.
[0215] In Formulas (M1) and (M2), Y is each independently a single
bond or a C.sub.1-20 alkylene, in which arbitrary --CH.sub.2-- may
be substituted with --O--, --S--, CH.dbd.CH--, --C.ident.C--,
--COO-- or --OCO--. Y is preferably a single bond,
--(CH.sub.2).sub.m2--, --O(CH.sub.2).sub.m2-- and
--(CH.sub.2).sub.m2O-- (where m2 is an integer of 1-20).
Particularly preferably, Y is a single bond, --(CH.sub.2).sub.m2--,
--O(CH.sub.2).sub.m2-- and --(CH.sub.2).sub.m2O-- (where m2 is an
integer of 1-10). In consideration of the stability of the
compound, --Y--R.sup.a and --Y--R.sup.b are preferably those not
having --O--O--, --O--S--, --S--O--, or --S--S--.
[0216] In Formulas (M1) and (M2), Z.sup.M is each independently a
single bond, --(CH.sub.2).sub.m3--, --O(CH.sub.2).sub.m3--,
--(CH.sub.2).sub.m3O--, --O(CH.sub.2).sub.m3O--, --CH.dbd.CH--,
--C.ident.C--, --COO--, --OCO--, --(CF.sub.2).sub.2--,
--(CH.sub.2).sub.2--COO--, --OCO--(CH.sub.2).sub.2--,
--CH.dbd.CH--COO--, --OCO--CH.dbd.CH--, --C.ident.C--COO--,
--OCO--C.ident.C--, --CH.dbd.CH--(CH.sub.2).sub.2--,
--(CH.sub.2).sub.2--CH.dbd.CH--, --CF.dbd.CF--,
--C.ident.C--CH.dbd.CH--, --CH.dbd.CH--C.ident.C--,
--OCF.sub.2--(CH.sub.2).sub.2--, --(CH.sub.2).sub.2--CF.sub.2O--,
--OCF.sub.2-- or --CF.sub.2O-- (where m3 is an integer of
1-20).
[0217] Z.sup.M is preferably a single bond, --(CH.sub.2).sub.m3--,
--O(CH.sub.2).sub.m3--, --(CH.sub.2).sub.m3O--, --CH.dbd.CH--,
--C.ident.C--, --COO--, --OCO--, --(CH.sub.2).sub.2--COO--,
--OCO--(CH.sub.2).sub.2--, --CH.dbd.CH--COO--, --OCO--CH.dbd.CH--,
--OCF.sub.2-- and --CF.sub.2O--.
[0218] In Formulas (M1) and (M2), m1 is an integer of 1-6, and
preferably an integer of 1-3. When m1 is 1, they are bicyclic
compounds having two, for example, 6-membered rings. When m1 is 2
or 3, they are separately tricyclic and tetracyclic compounds. For
example, when m1 is 1, the two A.sup.Ms can be identical or
different. Moreover, for example, when m1 is 2, the three A.sup.Ms
(or two Z.sup.Ms) can be identical or different. When m1 is 3-6, it
is also the case. The case is also applicable to R.sup.a, R.sup.b,
R.sup.d, Z.sup.M, A.sup.M and Y.
[0219] Even the Compound (M1) of Formula (M1) and the Compound (M2)
of Formula (M2) contains an isotope in an amount higher than the
relative isotopic abundance, such as .sup.2H (deuterium) and
.sup.13C, the Compound (M1) and the Compound (M2) are useful, due
to the identical properties.
[0220] More preferred examples of Compounds (M1) and (M2) are
Compounds (M1-1)-(M1-41) and (M2-1)-(M2-27). In these compounds,
R.sup.a, R.sup.b, R.sup.d, Z.sup.M, A.sup.M, Y and p are defined as
in the cases of Formulas (M1) and (M2) in the above aspects of the
present invention.
[0221] Partial structures of Compounds (M1-1)-(M1-41) and Compounds
(M2-1)-(M2-27) are described as follows. Partial Structure (a1)
represents 1,4-phenylene in which arbitrary hydrogen atom is
substituted with fluorine. Partial Structure (a2) represents
1,4-phenylene in which arbitrary hydrogen is substituted with
fluorine. Partial Structure (a3) represents 1,4-phenylene in which
arbitrary hydrogen is substituted with fluorine or methyl. Partial
Structure (a4) represents fluorene in which hydrogen at position 9
may be substituted with methyl.
##STR00082## ##STR00083## ##STR00084## ##STR00085## ##STR00086##
##STR00087## ##STR00088##
[0222] A monomer having no mesogen moiety and a polymerizable
compound having a mesogen moiety other than the monomers (M1) and
(M2) can be used, if desired.
[0223] In order to optimize the optical isotropy of the
polymer/liquid crystal composite material of the present invention,
a monomer having a mesogen moiety and three or more polymerizable
functional groups can be used. The monomer having s mesogen moiety
and three or more polymerizable functional groups is preferably a
well-know compound, for example, (M4-1)-(M4-3), and more
specifically, the compounds described in Japanese Patent
Publication Nos. 2000-327632, 2004-182949, and 2004-59772. In
(M4-1)-(M4-3), R.sup.b, Za, Y, and (F) are defined as above.
##STR00089##
[0224] 5.2.2 Monomer Having No Mesogen Moiety and Having
Polymerizable
Functional Group
[0225] Examples of the monomer having no mesogen moiety and having
a polymerizable group are linear or branched acrylate of 1-30
carbons, linear or branched diacrylate of 1-30 carbons, and a
monomer having three or more polymerizable groups, for example, but
not limited to, glycerol-propoxide (1PO/OH) triacrylate,
pentaerythritol-propoxide triacrylate, pentaerythritol triacrylate,
trihydroxylmethylpropane-ethoxide triacrylate,
trihydroxylmethylpropane-propoxide triacrylate,
trihydroxylmethylpropane triacrylate, di(trihydroxylmethylpropane)
tetraacrylate, pentaerythritol tetraacrylate, di(pentaerythritol)
pentaacrylate, di(pentaerythritol) hexaacrylate, and
trihydroxylmethylpropane triacrylate.
[0226] 5.2.3 Polymerization Initiator
[0227] The polymerization pattern used to produce the polymer
forming the composite material of the present invention has no
particular limitation, and can be, for example, photo-radical
polymerization, thermo-radical polymerization, and photo-cationic
polymerization.
[0228] The photo-radical polymerization initiator useful for
photo-radical polymerization are, for example, DAROCUR.TM. 1173,
and 4265 (both are trade names, from Ciba Specialty Chemicals); and
IRGACURE.TM. 184, 369, 500, 651, 784, 819, 907, 1300, 1700, 1800,
1850, and 2959 (all are trade names, from Ciba Specialty
Chemicals).
[0229] Preferred examples of the initiators causing radical
polymerization with heating and being useful in thermo-radical
polymerization are benzoyl peroxide, diisopropyl peroxydicarbonate,
tert-butyl peroxy(2-ethylhexanoate), tert-butyl peroxypivalate,
tert-butyl peroxydiisobutyrate, lauroyl peroxide, dimethyl
2,2'-azobisisobutyrate (MAIB), di-t-butyl peroxide (DTBPO),
azobisisobutyronitrile (AIBN), and azobiscyclohexanecarbonitrile
(ACN), and the like.
[0230] Examples of the photo-cationic polymerization initiator
useful for photo-cationic polymerization are diaryliodonium salt
(referred to as "DAS", hereinafter), and triarylsulfonium salt
(referred to as "TAS", hereinafter), and the like.
[0231] Examples of DAS are diphenyliodonium tetrafluoroborate,
diphenyliodonium hexafluorophosphonate, diphenyliodonium
hexafluoroarsenate, diphenyliodonium trifluoromesylate,
diphenyliodonium trifluoroacetate, diphenyliodonium
p-toluenesulfonate, diphenyliodonium
tetrakis(pentafluorophenyl)borate, 4-methoxyphenylphenyliodonium
tetrafluoroborate, 4-methoxyphenylphenyliodonium
hexafluorophosphonate, 4-methoxyphenylphenyliodonium
hexafluoroarsenate, 4-methoxyphenylphenyliodonium
trifluoromesylate, 4-methoxyphenylphenyliodonium trifluoroacetate,
and 4-methoxyphenylphenyliodonium p-toluenesulfonate, and the
like.
[0232] DAS may be sensitized by adding a photosensitizer, such as
thioxanthone, phenothiazine, chlorothioxanthone, xanthone,
anthracene, diphenyl anthracene, and rubrene.
[0233] Examples of TAS are triphenylsulfonium tetrafluoroborate,
triphenylsulfonium hexafluorophosphonate, triphenylsulfonium
hexafluoroarsenate, triphenylsulfonium trifluoromesylate,
triphenylsulfonium trifluoroacetate, triphenylsulfonium
p-toluenesulfonate, triphenylsulfonium
tetrakis(pentafluorophenyl)borate, 4-methoxyphenyldiphenylsulfonium
tetrafluoroborate, 4-methoxy phenyldiphenylsulfonium
hexafluorophosphonate, 4-methoxyphenyldiphenylsulfonium
hexafluoroarsenate, 4-methoxyphenyldiphenylsulfonium
trifluoromesylate, 4-methoxyphenyldiphenylsulfonium
trifluoroacetate, and 4-methoxyphenyldiphenylsulfonium
p-toluenesulfonate, and the like.
[0234] Specific examples of the photo-cationic polymerization
initiator are Cyracure.TM. UV1-6990, Cyracure UV1-6974, and
Cyracure UV1-6992 (all are trade names, from UCC Corporation);
Adeka Optomer SP-150, SP-152, SP-170, and SP-172 (all are trade
names, from ADEKA Corporation); Rhodorsil Photoinitiator 2074
(trade name, from RHODIA JAPAN Corporation); IRGACURE.TM. 250
(trade name, from Ciba Specialty Chemicals); and UV-9380C (trade
name, from GE TOSHIBA SILICONES Co. Ltd), and the like.
[0235] 5.2.4 Curing Agents and Others
[0236] In preparing the polymer forming the composite material of
the present invention, in addition to the monomers and
polymerization initiator above, one or two or more other preferred
component(s) may also be further added, for example, curing agent,
catalyst, and stabilizer.
[0237] The latent curing agents well-known in the art which are
commonly used for epoxy resins curing agent can be used. Examples
of the latent curing agent for epoxy resins are amine curing
agents, novolac-based curing agents, imidazole curing agents, and
anhydride-based curing agents, and the like. Examples of amine
curing agents are aliphatic polyamines such as diethylenetriamine,
triethylenetetraamine, tetraethylenepentaamine, m-xylenediamine,
trimethyl hexamethylenediamine, 2-methyl hexamethylenediamine, and
diethylaminopropylamine; alicyclic polyamines such as isophorone
diamine, 1,3-diaminomethylcyclohexane,
bis(4-aminocyclohexyl)methane, norbornanediamine,
1,2-diaminocyclohexane, and Laromin; and aromatic polyamines such
as diaminodiphenylmethane, diaminodiphenylethane, and
m-phenylenediamine.
[0238] Examples of novolac-based curing agents are phenol-Novolac
resin, and bisphenol-Novolac resin, and the like. Examples of the
imidazole curing agents are 2-methylimidazole,
2-ethylhexylimidazole, 2-phenylimidazole, and
1-cyanoethyl-2-phenylimidazolium trimellitate, and the like.
[0239] Examples of anhydride-based curing agents are
tetrahydrophthalic anhydride, hexahydrophthalic anhydride,
methyltetrahydrophthalic anhydride, methylhexahydrophthalic
anhydride, methylcyclohexene tetracarboxylic dianhydride, phthalic
anhydride, trimellitic anhydride, pyromellitic anhydride, and
benzophenonetetracarboxylic dianhydride, and the like.
[0240] Furthermore, a curing promoter can further be used to
facilitate the curing reaction of a polymerizable compound with
glycidyl, epoxy, and oxetanyl and the curing agent. Examples of the
curing promoter are tertiary amines such as benzyldimethylamine,
tris(dimethylaminomethyl)phenol, and dimethylcyclohexylamine;
imidazoles such as 1-cyanoethyl-2-ethyl-4-methylimidazole, and
2-ethyl-4-methylimidazole; organophosphorus compounds such as
triphenylphosphine; quaternary phosphosium salts such as
tetraphenylphosphosium bromide; diazobicyclo alkenes such as
1,8-diazobicyclo[5.4.0]undecene-7 or an organic acid salt thereof;
quaternary ammonium salts such as tetraethylammonium bromide, and
tetrabutylammonium bromide; boron compounds such as boron
trifluoride, and triphenyl borate, and the like. These curing
promoters can be used alone, or in a combination of two or
more.
[0241] Moreover, a stabilizer is preferably added to prevent
unwanted polymerization, for example, during storage. The
stabilizer can be any compound well known to those of ordinary
skill in the art, and representative examples are 4-ethoxyphenol,
hydroquinone, and butylated hydroxytoluene (BHT), and the like.
[0242] 5.3 Content of Liquid Crystal Composition
[0243] The content of the liquid crystal composition in the
polymer/liquid crystal composite material of the present invention
is preferably as high as possible, provided that it is within a
range in which the composite material can exhibit an optically
isotropic liquid crystal phase. This is because that the
electrically controlled birefringence value of the composite
material of the present invention is greater when the content of
the liquid crystal composition is higher.
[0244] In the polymer/liquid crystal composite material of the
present invention, the content of the liquid crystal composition is
preferably 60-99 wt %, more preferably 60-95 wt %, and particularly
preferably 65-95 wt %, based on the composite material. The content
of the polymer is preferably 1-40 wt %, more preferably 5-40 wt %,
and particularly preferably 5-35 wt %, based on the composite
material.
[0245] 5.4 Other Components
[0246] The polymer/liquid crystal composite material of the present
invention can also contain, for example, a dichroic dye and a
photochromic compound, without compromising the effects of the
present invention.
[0247] The present invention is further described in detail with
reference to examples; however, the present invention is not
limited to thereto. Furthermore, "%" denotes "wt %", unless
specifically indicated.
[0248] 6 Optical Device
[0249] A sixth aspect of the present invention is an optical
device, which contains the liquid crystal composition or the
polymer/liquid crystal composite material (hereinafter, both are
sometimes collectively referred to as liquid crystal medium) and is
driven in an optically isotropic liquid crystal phase.
[0250] The liquid crystal medium is optically isotropic in the
absence of an electric field and exhibits an optical anisotropy in
the presence of an electric field, such that optical modulation can
be achieved with an electric field.
[0251] The structure of the LCD device is, for example, as shown in
FIG. 1, in which the electrodes on the comb-like electrode
substrate have such a structure that Electrode 1 extending from the
left side and Electrode 2 extending from the right side are
alternatively arranged. When a potential difference exists between
Electrode 1 and Electrode 2, the comb-like electrode substrate is
provided with an electric field in two directions (upward and
downward), as shown in FIG. 1.
EXAMPLES
[0252] The resulting compound is characterized with nuclear
magnetic resonance (NMR) spectrum using .sup.1H-NMR analysis and
gas chromatogram obtained from gas chromatography (GC) analysis.
The analysis methods are firstly illustrated below.
[0253] .sup.1H-NMR analysis: .sup.1H-NMR analysis was carried out
by using DRX-500 (manufactured by Bruker BioSpin Co., Ltd.). In the
measurement, a sample prepared in an example was dissolved in a
deuterated solvent, such as CDCl.sub.3, capable of dissolving the
sample, and then was measured with a NMR apparatus at 500 MHz at
room temperature in 24 times of accumulation. In the resulting NMR
spectrum, s denotes singlet, d denotes doublet, t denotes triplet,
q denotes quartet, and m denotes multiplet. Furthermore,
tetramethylsilane (TMS) was used as the standard of chemical shift
.delta. of zero.
[0254] GC analysis: GC analysis was carried out by using a GC
apparatus Model GC-14B (manufactured by Shimazu). The column was
the capillary column CBP1-M25-025 (manufactured by Shimazu; length
25=m, inner diameter=0.22 mm, film thickness=0.25 .mu.m); and the
stationary liquid phase was dimethicone; non-polarity). The carrier
gas was helium, and the flow rate was adjusted to 1 ml/min. The
sample evaporation chamber was set at 300.degree. C., and the
detector (flame ionization detector, FID) was set at 300.degree.
C.
[0255] A sample was dissolved in toluene to give a solution of 1 wt
%, and then 1 .mu.l of the solution was injected into the sample
evaporation chamber.
[0256] The recorder used was Chromatopac Model C--R6A (manufactured
by Shimazu) or an equivalent thereof. The resulting gas
chromatogram exhibited peak retention times and peak areas
corresponding to the component compounds.
[0257] Furthermore, the solvent for diluting the sample was, for
example, chloroform or hexane. The column used was, for example,
capillary column DB-1 (length=30 m, inner diameter=0.32 mm, film
thickness=0.25 .mu.m, manufactured by Agilent Technologies Inc.),
HP-1 (length=30 m, inner diameter=0.32 mm, film thickness=0.25
p.m., manufactured by Agilent Technologies Inc.), Rtx-1 (length=30
m, inner diameter=0.32 mm, film thickness=0.25 .mu.m, manufactured
by Restek Corporation), or BP-1 (length=30 m, inner diameter=0.32
mm, film thickness=0.25 .mu.m, manufactured by SGE International
Pty. Ltd.).
[0258] The area ratios of the peaks in the gas chromatogram
correspond to the ratios of the component compounds. Generally, the
weight percentages of the component compounds in the analyzed
sample are not completely identical to the area percentages of the
peaks. However, in the present invention, when the columns above
are used, the correction coefficient is substantially 1. Therefore,
the weight percentages of the component compounds in the analyzed
sample are substantially equivalent to the area percentages of the
peaks. The reason lies in that there is no significant difference
among the correction coefficients of the component compounds. In
order to more accurately calculate the ratios of the liquid crystal
compounds in the liquid crystal composition with GC, the internal
standard method for GC can be used. GC measurements were
simultaneously performed on an accurately weighed specified amount
of a liquid crystal compound component (component to be detected)
and a liquid crystal compound (standard substance) as standard, and
the relative intensity was previously calculated as peak area ratio
of the detected component to the standard. If a correction was done
by using the relative intensity expressed as peak area ratio of
each component to the standard, then the ratios of the liquid
crystal compounds in the liquid crystal composition can be more
accurately calculated with GC analysis.
[0259] Samples for Determining Characteristic Values of Liquid
Crystal Compounds
[0260] Upon measuring the characteristic values of a liquid crystal
compound, there are two situations, i.e., taking a compound per se
as a sample, and mixing a compound in a mother liquid crystal to
form a sample.
[0261] As for the latter situation of using a sample prepared by
mixing a compound with a mother liquid crystal, the following
method is used for the measurement. First, 15 wt % of the resulting
liquid crystal compound was mixed with 85 wt % of the mother liquid
crystal to prepare a sample, and then the characteristic values of
the compound are calculated from the measured value obtained with
the extrapolation method according to the equation below.
[Extrapolated Value]=(100.times.[measured value of the sample]-[wt
% of the mother liquid crystal].times.[measured value of the mother
liquid crystal])/[wt % of the liquid crystal compound]
[0262] While a smectic phase or a crystal may be deposited at the
ratio above of a liquid crystal compound and a mother liquid
crystal at 25.degree. C., the ratio of the liquid crystal compound
and the mother liquid crystal is changed to 10 wt %:90 wt %, 5 wt
%:95 wt %, 1 wt %:99 wt % in order. The composition without
deposition of a smectic phase or a crystal at 25.degree. C. was
measured for the characteristic values, and the extrapolation is
calculated based on above equation as the characteristic values of
the liquid crystal compound.
[0263] There are numerous mother liquid crystals that can be used
for the measurement. For example, the composition of the mother
liquid crystal A is as follows (wt %).
Mother Liquid Crystal A:
##STR00090##
[0265] Method for Measuring Characteristic Values of Liquid Crystal
Compounds
[0266] The measurement of the characteristic values was carried out
with the methods below. These methods are mainly those described in
EIAJ.cndot.ED-2521A of the Standard of Electric Industries
Association of Japan, or modifications of the same. Moreover, the
TN device used in the measurement was not equipped with TFT.
[0267] With respect to the determined values, in case that the
liquid crystal compound itself is used as a sample, the obtained
values are recorded as experimental data; and in case that a
mixture of the liquid crystal compound and a mother liquid crystal
is used as a sample, the extrapolated values obtained with the
extrapolation method are recorded as experimental data.
[0268] The phase structure and the phase transition temperature
(.degree. C.) were measured by using Method (1) and Method (2)
below.
[0269] (1) A compound was placed on a heating plate (Hot Stage,
Model FP-52, manufactured by Mettler Corp.) in a melting point
measuring apparatus equipped with a polarizing microscope, and the
phase behaviour and its change were observed by the polarizing
microscope while the sample was heated at a rate of 3.degree.
C./min to determine the type of the liquid crystal phase.
[0270] (2) A scanning calorimetry DSC-7 system or Diamond DSC
system (manufactured by PerkinElmer Corp.) was used, at a heating
or cooling rate of 3.degree. C./min, and the on-set temperature of
the endothermic peak or the exothermic peak accompanying with the
phase change of the sample was calculated with the extrapolation
method, so as to determine the phase transition temperature.
[0271] Hereinafter, a crystal phase is expressed as K, and for
differentiation, two crystals are represented by K.sub.1 or K.sub.2
respectively. A smectic phase is represented by Sm, a nematic phase
is represented by N, and a liquid (isotropic phase) is represented
by I. For differentiation, a smectic B phase and a smectic A phase
in the smectic phase are presented by SmB and SmA respectively. BP
represents a blue phase or an optically isotropic liquid crystal
phase. A biphase co-existence is sometimes represented by (N*+I),
(N*+BP). Specifically, (N*+I) represents a phase in which a
non-liquid crystal isotropic phase and a chiral nematic phase
coexist respectively, and (N*+BP) represents a phase in which a BP
phase or an optically isotropic liquid crystal phase and a chiral
nematic phase coexist. Un represents a non-optically isotropic
unidentified phase. For the expression of the phase transition
temperature, for example, "K 50.0 N 100.01" means that the phase
transition temperature (KN) from the crystal to the nematic phase
is 50.0.degree. C., and the phase transition temperature (NI) from
the nematic phase to the liquid is 100.0.degree. C. This rule is
also applicable to other expressions.
[0272] Upper-limit temperature of a nematic phase (T.sub.NI,
.degree. C.): A sample (a mixture of a liquid crystal compound and
a mother liquid crystal) was placed on a heating plate (Hot Stage,
Model FP-52, manufactured by Mettler Corp.) in a melting point
measuring apparatus equipped with a polarizing microscope, and was
observed by the polarizing microscope while the sample was heated
at a rate of 1.degree. C./min. The temperature at which a part of
the sample began to change from a nematic phase to an isotropic
liquid was recorded as the upper-limit temperature of the nematic
phase, and sometimes abbreviated as "upper-limit temperature" of
the nematic phase below.
[0273] Low-temperature compatibility: Samples were prepared by
mixing a mother liquid crystal with a liquid crystal compound in a
manner such that the content of the latter was 20 wt %, 15 wt %, 10
wt %, 5 wt %, 3 wt %, and 1 wt %, respectively, and then placed
into glass bottles. The glass bottles were kept in a freezer at
-10.degree. C. or -20.degree. C. for a certain period of time, and
the presence or absence of a crystal or a smectic phase was
observed.
[0274] Viscosity (.eta., determined at 20.degree. C., mPas): The
viscosity of a mixture of a liquid crystal compound and a mother
liquid crystal is measured with an E-type viscometer.
[0275] Refractive index anisotropy (.DELTA.n): The measurement was
carried out at 25.degree. C. by using light having a wavelength of
589 nm, with an Abbe refractometer having a polarizing plate
mounted on the ocular lens. After the surface of the main prism is
rubbed in a direction, a sample (a mixture of a liquid crystal
compound and a mother liquid crystal) was dripped onto the main
prism. The refractive index (n.sub..parallel.) was determined when
the polarizing direction was paralleled to the rubbing direction,
and the refractive index (n.sub..perp.) was determined when the
polarizing direction was perpendicular to the rubbing direction.
The value of refractive index anisotropy (.DELTA.n) was calculated
according to the equation
.DELTA.n=n.sub..parallel.-n.sub..perp..
[0276] Dielectric anisotropy (.DELTA..di-elect cons.: determined at
25.degree. C.): A sample (a mixture of a liquid crystal compound
and a mother liquid crystal) was fed into a liquid crystal cell
with a distance (cell gap) of about 9 .mu.m between two glass
substrates and a twist angle of 80 degrees. The cell was applied
with a voltage of 20 V and the dielectric (.di-elect
cons..sub..parallel.) in the major-axis direction of the liquid
crystal molecule was determined. Then, a voltage of 0.5 V was
applied and the dielectric (.di-elect cons..sub..perp.) in the
minor axis direction of the liquid crystal molecule was determined.
The value of dielectric anisotropy was calculated according to the
equation .DELTA..di-elect cons.=.di-elect
cons..sub..parallel.-.di-elect cons..sub..perp.
[0277] Pitch (P, determined at 25.degree. C., m)
[0278] A pitch length was measured through selective reflection
(Handbook of Liquid Crystal, p 196, 2000, Maruzen). For the
selective reflection wavelength .lamda., the relationship
<n>p/.lamda.=1 exists. Herein, <n> denotes the average
refractive index, and can be calculated according to the equation
<n>={(n.sub..parallel..sup.2+n.sub..perp..sup.2)/2}.sup.1/2.
The selective reflection wavelength was determined by a
microspectrophotometer (Trade name MSV-350, manufactured by Japan
Electronics Co., Ltd.). The pitch was calculated by dividing the
resulting reflection wavelength with the average refractive index.
When the concentration of the optically active compound is low, the
pitch of a cholesteric liquid crystal having a reflection
wavelength in a region of wavelength longer than that of visible
light is proportional to the reciprocal of the concentration.
Therefore, multiple points were measured in the pitch length of the
liquid crystal having a selective reflection wavelength in the
visible light region, and then the pitch was calculated by using a
linear extrapolation method. The "optically active compound" is
equivalent to the chiral reagent in the present invention.
Example 1
Synthesis of Compound (S1-11)
[0279] Compound (S1-11) is a compound of Formula in which R.sup.1
is C.sub.4H.sub.9, L.sup.1 is hydrogen, L.sup.2, L.sup.4 and
L.sup.5 are all fluorine, and X.sup.1 is --CF.sub.3. (the same as
Compound (1-4-3-a))
##STR00091##
[0280] The synthesis scheme is shown below.
##STR00092## ##STR00093##
[0281] In the scheme, r.t. is room temperature.
Synthesis of Compound (S1-2)
[0282] Under nitrogen atmosphere, Grignard reagent was formulated
with 11.3 g of dry magnesium and 75.0 g of
1-bromo-3-chloro-5-fluorobenzene (S1-1) in 220 ml of
tetrahydrofuran (THF), and cooled to -70.degree. C. A solution of
52.0 g trimethyl borate in 200 ml THF was dropped, directly stirred
at -70.degree. C. for 3 hrs, then heated to room temperature for 1
hr, and stirred for 12 hrs. 2N hydrochloric acid was dropped to the
reaction solution and stirred for 1 hr, and the resulting product
was extracted with ethyl acetate, washed with water, dried, and
distilled off the solvent under vacuum. The residue was washed with
heptane to obtain 34.7 g of (S1-2). The yield of Compound (S1-2)
was 55.7%.
Synthesis of Compound (S1-4)
[0283] 64.5 g of 3-chloro-5-fluorophenylboric acid (S1-2), 110.0 g
of 1-bromo-3-fluoro-5-iodobenzene (S1-3), 6.0 g of
tetrakis(triphenylphosphine)palladium, 130.0 g of potassium
carbonate, and 1000 ml of a mixed solvent of toluene/ethanol/water
3/3/1 (volume ratio) were added into a reactor under nitrogen
atmosphere, and refluxed for 40 hrs. The reaction solution was
cooled to room temperature, added with toluene, and then washed
with 1N hydrochloric acid, and water. Afterwards, the solution was
dried over magnesium sulfate, and then distilled under vacuum to
remove the solvent. Then, the product was purified by silica-gel
column chromatography with heptane as a developing solvent, and
then dried under vacuum to obtain 53.8 g of (S1-4). The yield of
Compound (S1-4) from (S1-3) was 48.5%.
Synthesis of Compound (S1-5)
[0284] 25.3 g of Compound (S1-4) and 250 ml of THF were added to a
reactor under nitrogen atmosphere, and then 120 ml of 0.91 M
butylmagnesium chloride was dropped at room temperature, and heated
to reflux for 6 hrs. After cooling to room temperature, 1N
hydrochloric acid was dropped, and stirred for 1 hrs. The resulting
product was extracted with toluene, and washed with water. The
product was dried over magnesium sulfate, and then the solvent was
distilled off under vacuum. The product was purified by silica-gel
column chromatography with heptane as a developing agent, and then
dried under vacuum to obtain 21.1 g of (S1-5). The yield of (S1-5)
from
[0285] (S1-4) was 90.2%.
Synthesis of Compound (S1-6)
[0286] 21.1 g of (S1-5) and 300 ml of tetrahydrofuran (THF) were
added to a reactor under nitrogen atmosphere, and cooled to
-70.degree. C. 56.4 ml of n-BuLi (1.6M; solution in n-hexane) was
dropped, and directly stirred at -70.degree. C. for 1 hr. At
-70.degree. C., a solution of 22.8 g iodine in 200 ml THF was
dropped to the reaction solution, and directly stirred at
-70.degree. C. for 1 hr. The reaction solution was heated to room
temperature, and poured into an aqueous sodium thiosulfate
solution. The resulting product was extracted with toluene, and the
organic layer was washed with an aqueous sodium thiosulfate
solution and water. The product was dried over magnesium sulfate,
and the solvent was distilled off under vacuum. The product was
purified by silica-gel column chromatography with heptane as a
developing agent, and then dried under vacuum to obtain 30.7 g of
(S1-6). The yield of (S1-6) from (S1-5) was 100%.
Synthesis of Compound (S1-8)
[0287] 30.7 g of (S1-6), 24.0 g of 3,5-difluorophenylboric acid
(S1-7), 5.0 g of tetrakis(triphenylphosphine)palladium, 25.0 g of
sodium carbonate, and 280 ml of a mixed solvent of
toluene/ethanol/water=3/3/1 (volume ratio) were added to a reactor
under nitrogen atmosphere, and refluxed for 30 hrs. 2.0 g of
additional tetrakis(triphenylphosphine)palladium was added and
further refluxed for 10 hrs. The reaction solution was cooled to
room temperature, added with toluene, and washed with 1N
hydrochloric acid, and water. The product was dried over magnesium
sulfate, and the solvent was removed under vacuum. The product was
purified by silica-gel column chromatography with heptane as a
developing agent, and then dried under vacuum to obtain 14.5 g of
(S1-8). The yield of (S1-8) from (S1-6) was 48.9%.
Synthesis of Compound (S1-9)
[0288] 14.5 g of Compound (S1-8) and 100 ml of THF were added to a
reactor under nitrogen atmosphere, and cooled to -74.degree. C.
26.8 ml of a 1.59 M solution of n-butyllithium in n-hexane was
dropped at a temperature in the range from -74.degree. C. to
-60.degree. C., and further stirred for 60 min. Subsequently, a
solution of 12.0 g dibromodifluoromethane in 20.0 ml THF was
dropped at a temperature in the range from -75.degree. C. to
-70.degree. C., and warmed to 25.degree. C. with stirring for 60
min. The resulting reaction mixture was poured into 150 ml of ice
water and mixed. 100 ml of toluene was added to separate the
organic layer and the aqueous layer for extraction. The resulting
organic layer was decanted, washed with saline, and dried over
anhydrous magnesium sulfate. The resulting solution obtained under
vacuum was concentrated, and the residue was purified by silica-gel
column chromatography with heptane as a developing agent. The
product was dried by distilling off the solvent to obtain 16.5 g of
(S1-9) as a crude product.
Synthesis of Compound (S1-11)
[0289] 16.5 g of Compound (S1-9), 5.0 g of
3,5-difluoro-4-trifluoromethylphenol (S1-10), 10.5 g of potassium
carbonate, 0.5 g of tetrabutylammonium bromide, and 150 ml of
N,N-dimethylformamide (DMF) were added into a reactor under
nitrogen atmosphere, and stirred for 90 min at 95.degree. C. After
being warmed to 25.degree. C., the reaction mixture was poured into
50 ml of ice water and mixed, 100 ml of toluene was added to
separate the organic layer from the aqueous layer for extraction,
the organic layer was decanted, washed with a saturated aqueous
sodium bicarbonate solution and saline, and dried over anhydrous
magnesium sulfate. The resulting solution was concentrated under
vacuum, and the residue was purified by silica-gel column
chromatography with heptane as a developing agent. The product was
further purified by recrystallized in a mixed solvent of
ethanol/ethyl acetate=9/1, and dried to obtain 5.5 g of (S1-11).
The yield of (S1-11) from (S1-8) was 23.3%.
[0290] The phase transition temperature of the resulting Compound
(S1-11) is as follows.
[0291] Phase transition temperature (.degree. C.): K 83.7 I.
[0292] It can be known that the melting point of Compound (S1-11)
is low.
[0293] The resulting compound was identified as (S1-9) from the
following chemical shifts .delta.(ppm) obtained with .sup.1H-NMR
analysis in which CDCl.sub.3 was used as a solvent. Chemical shifts
.delta.(ppm): 7.53 (m, 1H), 7.37-7.33 (m, 2H), 7.12-7.07 (m, 3H),
7.04-7.01 (m, 3H), 2.67 (t, 2H), 1.67-1.61 (m, 2H), 1.43-1.35 (m,
2H), 0.96 (t, 3H).
[0294] Physical Properties of Liquid Crystal Compound (S1-11)
[0295] The four compounds designated as mother liquid crystal A
above were mixed, to prepare a mother liquid crystal A having a
nematic phase. The physical properties of the mother liquid crystal
A are as follows.
[0296] Upper-limit temperature (T.sub.N1)=71.7.degree. C.;
dielectric anisotropy (.DELTA..di-elect cons.)=11.0; and refractive
index anisotropy (.DELTA.n)=0.137.
[0297] A liquid crystal composition AS1 containing 90 wt % of the
mother liquid crystal A and 10 wt % of (S1-10) obtained in Example
was prepared, and the characteristic values were determined. The
extrapolated characteristic values of the liquid crystal compound
(S1-11) calculated based on the measurements using an extrapolation
method are as follows.
[0298] Upper-limit temperature (T.sub.NI)=14.7.degree. C.;
dielectric anisotropy (.DELTA..di-elect cons.)=63.7; refractive
index anisotropy (.DELTA.n)=0.137.
[0299] It can be seen from the results that the liquid crystal
compound (S1-11) is well compatible with other liquid crystal
compounds, and has a large dielectric anisotropy (.DELTA..di-elect
cons.) and refractive index anisotropy (.DELTA.n).
Example 2
Synthesis of Compound (S2-1)
[0300] Compound (S2-1) is a compound of Formula (1-4-3), in which
R.sup.1 is C.sub.5H.sub.11, L.sup.1 is hydrogen, L.sup.2, L.sup.4
and L.sup.5 are all fluorine, and X.sup.1 is --CF.sub.3.
##STR00094##
Synthesis of Compound (S2-1)
[0301] Synthesis of (S2-1) was accomplished according to the method
for synthesizing (S1-11) in Example 1. The phase transition
temperature of the resulting Compound (S2-1) is as follows.
[0302] Phase transition temperature (.degree. C.): K 91.4 (N 34.4)
I.
[0303] The resulting compound was identified as (S2-1) .sup.1H-NMR
from the following chemical shifts .delta. (ppm) obtained with
.sup.1H-NMR analysis in which CDCl.sub.3 was used as a solvent.
Chemical shifts .delta.(ppm): 7.53 (m, 1H), 7.37-7.33 (m, 2H),
7.12-7.07 (m, 3H), 7.04-7.01 (m, 3H), 2.66 (t, 2H), 1.69-1.63 (m,
2H), 1.41-1.31 (m, 4H), 0.92 (t, 3H).
Comparative Example 1
[0304] Compound (Ref-1)
##STR00095##
[0305] The phase transition temperature of Compound (Ref-1) is as
follows.
[0306] Phase transition temperature (.degree. C.): K 102.0 I.
[0307] It can be known that Compound (S2-2) in Example 2 has a
melting point that is 10.6.degree. C. lower than that of Compound
(Ref-1), and is a compound having excellent compatibility.
Example 3
Synthesis of compound (S3-1)
[0308] Compound (S3-1) is a compound of Formula (1-4-3), in which
R.sup.1 is C.sub.6H.sub.13, L.sup.1 is hydrogen, L.sup.2, L.sup.4
and L.sup.5 are all fluorine, and X.sup.1 is --CF.sub.3. (The same
as Compound (1-4-3-c))
##STR00096##
Synthesis of Compound (S3-1)
Synthesis of (S3-1) was accomplished according to the process for
synthesizing (S1-11) in Example 1. The phase transition temperature
of the resulting Compound (S3-1) is as follows.
[0309] Phase transition temperature (.degree. C.): K 69.4 (N 27.7)
I.
[0310] The resulting compound was identified as (S3-1) from the
following chemical shifts .delta.(ppm) obtained with .sup.1H-NMR
analysis in which CDCl.sub.3 was used as a solvent.
[0311] Chemical shifts .delta. (ppm): 7.53 (m, 1H), 7.37-7.33 (m,
2H), 7.12-7.07 (m, 3H), 7.04-7.01 (m, 3H), 2.66 (t, 2H), 1.68-1.62
(m, 2H), 1.39-1.29 (m, 6H), 0.90 (t, 3H).
[0312] Physical Properties of Liquid Crystal Compound (S3-1)
[0313] The four compounds designated as mother liquid crystal A
above were mixed, to prepare a mother liquid crystal A having a
nematic phase. The physical properties of the mother liquid crystal
A are as follows.
[0314] Upper limit temperature (T.sub.N1)=71.7.degree. C.;
dielectric anisotropy (.DELTA..di-elect cons.)=11.0; and refractive
index anisotropy (.DELTA.n)=0.137.
[0315] A liquid crystal composition AS3 containing 85 wt % of
mother liquid crystal A and 15 wt % of (S3-1) obtained in Example 3
was prepared, and the characteristic values were determined. The
extrapolated characteristic values of the liquid crystal compound
(S3-1) calculated based on the measurements using an extrapolation
method are as follows.
[0316] Upper limit temperature (T.sub.N1)=18.4.degree. C.;
dielectric anisotropy (.DELTA..di-elect cons.)=59.7; and refractive
index anisotropy (.DELTA.n)=0.130.
[0317] It can be seen from the results that the liquid crystal
compound (S3-1) is well compatible with other liquid crystal
compounds, and has a large dielectric anisotropy (.DELTA..di-elect
cons.) and refractive index anisotropy (.di-elect cons.n).
Example 4
Synthesis of Compound (S4-1)
[0318] Compound (S4-1) is a compound of Formula (1-1-2), in which
R.sup.1 is C.sub.6H.sub.13, L.sup.1 and L.sup.3 are both hydrogen,
L.sup.2, L.sup.4 and L.sup.5 are all fluorine, and X.sup.1 is
fluorine.
##STR00097##
Synthesis of Compound (S4-1)
[0319] Synthesis of (S4-1) was accomplished according to the
process for synthesizing (S1-11) in Example 1. The phase transition
temperature of the resulting Compound (S4-1) is as follows.
[0320] Phase transition temperature (.degree. C.): K 82.9 N 136.6
I.
[0321] The resulting compound was identified as (S3-1) from the
following chemical shifts .delta. (ppm) obtained with .sup.1H-NMR
analysis in which CDCl.sub.3 was used as a solvent. Chemical shifts
.delta. (ppm): 7.53 (m, 1H), 7.41-7.34 (m, 3H), 7.23-7.18 (m, 4H),
7.11-7.02 (m, 4H), 2.66 (t, 2H), 1.67-1.62 (m, 2H), 1.39-1.32 (m,
6H), 0.90 (t, 3H).
[0322] A liquid crystal composition AS4 containing 85 wt % of
mother liquid crystal. A and 15 wt % of (S4-1) obtained in Example
4 was prepared, and the characteristic values were determined. The
extrapolated characteristic values of the liquid crystal compound
(4-1) calculated based on the measurements using an extrapolation
method are as follows.
[0323] Upper limit temperature (T.sub.N1)=72.4.degree. C.;
dielectric anisotropy (.DELTA..di-elect cons.)=54.1; and refractive
index anisotropy (.DELTA.n)=0.177.
[0324] It can be seen from the results that the liquid crystal
compound (S4-1) is well compatible with other liquid crystal
compounds, and has a high clear point, dielectric anisotropy
(.DELTA..di-elect cons.), and refractive index anisotropy
(.DELTA.n).
Example 5
Synthesis of Compound (S5-1)
[0325] Compound (S5-1) is a compound of Formula (1-4-3), in which
R.sup.1 is C.sub.8H.sub.17, L.sup.1 is hydrogen, L.sup.2, L.sup.4
and L.sup.5 are all fluorine, and X.sup.1 is --CF.sub.3.
##STR00098##
Synthesis of Compound (S5-1)
[0326] Synthesis of (S5-1) was accomplished according to the
process for synthesizing (S1-11) in Example 1. The phase transition
temperature of the resulting Compound (S5-1) is as follows.
[0327] Phase transition temperature (.degree. C.): K 72.5 I.
[0328] A liquid crystal composition AS5 containing 85 wt % of
mother liquid crystal A and 15 wt % of (S5-1) obtained in Example 5
was prepared, and the characteristic values were determined. The
extrapolated characteristic values of the liquid crystal compound
(5-1) calculated based on the measurements using an extrapolation
method are as follows.
[0329] Upper limit temperature (T.sub.NI)=21.0.degree. C.;
dielectric anisotropy (.DELTA..di-elect cons.)=55.6; and refractive
index anisotropy (.DELTA.n)=0.130.
[0330] It can be seen from the results that the liquid crystal
compound (S5-1) is well compatible with other liquid crystal
compounds, and has a large dielectric anisotropy (.DELTA..di-elect
cons.) and refractive index anisotropy (.DELTA.n).
Example 6
Synthesis of Compound (S6-1)
[0331] Compound (S6-1) is a compound of Formula (1-1-2), in which
R.sup.1 is C.sub.8H.sub.17, L.sup.1 and L.sup.3 are both hydrogen,
L.sup.2, L.sup.4 and L.sup.5 are all fluorine, and X.sup.1 is
fluorine.
##STR00099##
Synthesis of Compound (S6-1)
[0332] Synthesis of (S6-1) was accomplished according to the
process for synthesizing (S1-11) in Example 1. The phase transition
temperature of the resulting Compound (S6-1) is as follows.
[0333] Phase transition temperature (.degree. C.): K 68.6 N 126.8
I.
[0334] A liquid crystal composition AS6 containing 85 wt % of
mother liquid crystal A, and 15 wt % of (S6-1) obtained in Example
6 was prepared, and the characteristic values were determined. The
extrapolated characteristic values of the liquid crystal compound
(6-1) calculated based on the measurements using an extrapolation
method are as follows.
[0335] Upper limit temperature (T.sub.NI)=73.7.degree. C.;
dielectric anisotropy (.DELTA..di-elect cons.)=50.3; and refractive
index anisotropy (.DELTA.n)=0.177.
[0336] It can be seen from the results that the liquid crystal
compound (S6-1) is well compatible with other liquid crystal
compounds, and has a high clear point, dielectric anisotropy
(.DELTA..di-elect cons.) and refractive index anisotropy
(.DELTA.n).
Example 7
Synthesis of Compound (S7-1)
[0337] Compound (S7-1) is a compound of Formula (1-6-2), in which
R.sup.1 is C.sub.6H.sub.13, L.sup.3 is hydrogen, L.sup.4 and
L.sup.5 are both fluorine, and X.sup.1 is fluorine.
##STR00100##
[0338] Phase Transition Point of Compound (S7-1)
[0339] Phase transition temperature of Compound (S7-1) is as
follows.
[0340] Phase transition temperature (.degree. C.): K 61.4 (N 13.5)
I.
[0341] A liquid crystal composition AS7 containing 85 wt % of
mother liquid crystal A and 15 wt % of (S7-1) obtained in Example 7
was prepared, and the characteristic values were determined. The
extrapolated characteristic values of the liquid crystal compound
(7-1) calculated based on the measurements using an extrapolation
method are as follows.
[0342] Upper limit temperature (T.sub.NI)=-3.6.degree. C.;
dielectric anisotropy (.DELTA..di-elect cons.)=45.7; and refractive
index anisotropy (.DELTA.n)=0.110.
[0343] It can be seen from the results that the liquid crystal
compound (S7-1) is well compatible with other liquid crystal
compounds, and has a dielectric anisotropy (.DELTA..di-elect
cons.).
Example 8
Synthesis of Compound (S8-1)
[0344] Compound (S8-1) is a compound of Formula (1-4-3), in which
R.sup.1 is C.sub.4H.sub.9, L.sup.1 is hydrogen, L.sup.2, L.sup.4
and L.sup.5 are all fluorine, and X.sup.1 is fluorine.
##STR00101##
Synthesis of Compound (S8-1)
[0345] Synthesis of (S8-1) was accomplished according to the
process for synthesizing (S1-11) in Example 1. The phase transition
temperature of the resulting Compound (S8-1) is as follows.
[0346] Phase transition temperature (.degree. C.): K 75.2 I.
[0347] A liquid crystal composition AS8 containing 85 wt % of
mother liquid crystal A and 15 wt % of (S8-1) obtained in Example 8
was prepared, and the characteristic values were determined. The
extrapolated characteristic values of the liquid crystal compound
(8-1) calculated based on the measurements using an extrapolation
method are as follows.
[0348] Upper limit temperature (T.sub.NI)=14.4.degree. C.;
dielectric anisotropy (A0=47.6; and refractive index anisotropy
(.DELTA.n)-0.130.
[0349] It can be seen from the results that the liquid crystal
compound (S8-1) is well compatible with other liquid crystal
compounds, and has a large dielectric anisotropy (.DELTA..di-elect
cons.) and refractive index anisotropy (.DELTA.n).
Example 9
Synthesis of Compound (S9-1)
[0350] Compound (S9-1) is a compound of Formula (1-4-3), in which
R.sup.1 is C.sub.5H.sub.11, L.sup.1 is hydrogen, L.sup.2, L.sup.4
and L.sup.5 are all fluorine, and X.sup.1 is fluorine.
##STR00102##
Synthesis of Compound (S9-1)
[0351] Synthesis of (S9-1) was accomplished according to the
process for synthesizing (S1-11) in Example 1. The phase transition
temperature of the resulting Compound (S9-1) is as follows.
[0352] Phase transition temperature (.degree. C.): K 56.6 (N 34.1)
I.
[0353] A liquid crystal composition AS9 containing 85 wt % of
mother liquid crystal A and 15 wt % of (S9-1) obtained in Example 9
was prepared, and the characteristic values were determined. The
extrapolated characteristic values of the liquid crystal compound
(9-1) calculated based on the measurements using an extrapolation
method are as follows.
[0354] Upper limit temperature (T.sub.N1)=19.7.degree. C.;
dielectric anisotropy (.DELTA..di-elect cons.)=49.6; refractive
index anisotropy (.DELTA.n)=0.137.
[0355] It can be seen from the results that the liquid crystal
compound (S9-1) is well compatible with other liquid crystal
compounds, and has a large dielectric anisotropy (.DELTA..di-elect
cons.) and refractive index anisotropy (.DELTA.n).
Example 10
Synthesis of Compound (S10-1)
[0356] Compound (S10-1) is a compound of Formula (1-4-3), in which
R.sup.1 is C.sub.6H.sub.13, L.sup.1 is hydrogen, L.sup.2, L.sup.4
and L.sup.5 are all fluorine, and X.sup.1 is fluorine.
##STR00103##
(Example 11)
[0357] Synthesis of Compound (S11-1)
[0358] Compound (S11-1) is a compound of Formula (1-1-2), in which
R.sup.1 is C.sub.5H.sub.11, L.sup.1 and L.sup.3 are both hydrogen,
L.sup.2, L.sup.4 and L.sup.5 are all fluorine, and X.sup.1 is
fluorine.
##STR00104##
Synthesis of Compound (S11-1)
[0359] Synthesis of (S11-1) was accomplished according to the
process for synthesizing (S1-11) in Example 1. The phase transition
temperature of the resulting Compound (S11-1) is as follows.
[0360] Phase transition temperature (.degree. C.): K 95.7 N 149.0
I.
[0361] A liquid crystal composition AS11 containing 90 wt % of
mother liquid crystal A and 10 wt % of (S11-1) obtained in Example
11 was prepared, and the characteristic values were determined. The
extrapolated characteristic values of the liquid crystal compound
(11-1) calculated based on the measurements using an extrapolation
method are as follows.
[0362] Upper limit temperature (T.sub.NI)=76.7.degree. C.;
dielectric anisotropy (.DELTA..di-elect cons.)=53.4; and refractive
index anisotropy (.DELTA.n)=0.187.
[0363] It can be seen from the results that the liquid crystal
compound (S11-1) has a high clear point, dielectric anisotropy
(.DELTA..di-elect cons.) and refractive index anisotropy
(.DELTA.n).
[0364] (Composition of the Present Invention)
[0365] In the present invention, the characteristic values of the
liquid crystal composition were measured according to the methods
below. The methods are mainly those described in
EIAJ.cndot.ED-2521A of the Standard of Electric Industries
Association of Japan, or modifications of the same. The TN device
used in the measurement was not equipped with TFT.
[0366] Upper-limit temperature of a nematic phase (NI, .degree.
C.): A sample was placed on a heating plate in a melting point
measuring apparatus equipped with a polarizing microscope, and
heated at a rate of 1.degree. C./min. The temperature at which a
part of the sample began to change from a nematic phase to an
isotropic liquid was determined. The upper-limit temperature of a
nematic phase which is sometimes abbreviated as "upper-limit
temperature".
[0367] Lower-limit temperature of a nematic phase (T.sub.c,
.degree. C.): A sample having a nematic phase was kept in a freezer
at 0.degree. C., -10.degree. C., -20.degree. C., -30.degree. C.,
and -40.degree. C. for 10 days, and observed for the liquid crystal
phase. For example, in a case where the sample exhibits a nematic
phase at -20.degree. C., and is changed to a crystal (or a smectic
phase) at -30.degree. C., the T.sub.c is recorded as
.gtoreq.-20.degree. C. The lower-limit temperature of a nematic
phase is sometimes abbreviated as "lower-limit temperature".
[0368] Transition temperature of an optically isotropic liquid
crystal phase: a sample was placed on a heating plate in a melting
point measuring apparatus equipped with a polarizing microscope
with crossed Nicols, which was initially heated to a temperature
allowing the sample to form a non-liquid crystal isotropic phase,
and then cooled at a rate of 1.degree. C./min until a chiral
nematic phase or an optically isotropic liquid crystal phase was
completely formed. The phase transition temperature during this
cooling process was measured. Then, the temperature was raised at a
rate of 1.degree. C./min, and the phase transition temperature
during this heating process was measured. In the present invention,
unless specifically indicated, the phase transition temperature in
the heating process was recorded as the phase transition
temperature. Where it was difficult to determine the phase
transition temperature of the optically isotropic liquid crystal
phase in a dark field under crossed Nicols, the phase transition
temperature could be determined after the polarizing plate is
deviated from the crossed Nicol state by 1-10 degrees.
[0369] Viscosity (.eta., determined at 20.degree. C., mPas): The
viscosity was measured with an E-type rotational viscometer.
[0370] Rotational viscosity (.gamma.l, determined at 25.degree. C.,
mPas):
[0371] 1) For a sample with a positive dielectric anisotropy: The
measurement was carried out according to the method described in M.
Imai et al., Molecular Crystals and Liquid Crystals, Vol. 259, 37
(1995). The sample was placed into a TN device with a twist angle
of 0 degree and a distance (cell gap) of 5 .mu.m between two glass
substrates. The TN device was applied with a voltage in a range of
16 to 19.5 V stepwise by 0.5 V. After a period of 0.2 s without
voltage application, a voltage application was repeated with a
rectangular wave (rectangular pulse of 0.2 s) followed by a period
of 2 s without voltage application. The peak current and the peak
time of the transient current resulted from the application of the
voltage were measured. Then, the value of rotational viscosity was
calculated according to the measurements and the Equation (8)
described in page 40 of the paper of M. Imai et al. The dielectric
anisotropy value required for this calculation was obtained by
using the device used in the measurement of the rotational
viscosity, according to the method for determining dielectric
anisotropy below.
[0372] 2) For a sample with a negative dielectric anisotropy: the
measurement was carried out according to the method described in M.
Imai et al., Molecular Crystals and Liquid Crystals, Vol. 259, 37
(1995). The sample was placed into a vertical alignment (VA) device
with a distance (cell gap) of 20 .mu.m between two glass
substrates. The device was applied with a voltage in a range of 30
to 50 V stepwise by 1 V. After a period of 0.2 s without voltage
application, a voltage application was repeated with a rectangular
wave (rectangular pulse of 0.2 s) followed by a period of 2 s
without voltage application. The peak current and the peak time of
the transient current resulted from the application of the voltage
were measured. Then, the value of rotational viscosity was
calculated according to the measurements and the Equation (8)
described in page 40 of the paper of M. Imai et al. The dielectric
anisotropy value required for this calculation was obtained by
using the method below.
[0373] Refractive index anisotropy (.DELTA.n, determined at
25.degree. C.): the measurement was carried out by using light
having a wavelength of 589 nm, with an Abbe refractometer having a
polarizing plate mounted on the ocular lens. After the surface of
the main prism was rubbed in a direction, the sample was dropped
onto the main prism. The refractive index (n.sub..parallel.) was
determined when the polarizing direction was paralleled to the
rubbing direction, and the refractive index (n.sub..perp.) was
determined when the polarizing direction was perpendicular to the
rubbing direction. The value of refractive index anisotropy was
calculated according the equation
.DELTA.n=n.sub..parallel.-n.sub..perp.. When the sample was a
composition, the process could be used to determine the refractive
index anisotropy. When the sample was a compound, the compound
could be mixed with a suitable composition and then determined for
the refractive index anisotropy of the mixture. In this case, the
refractive index anisotropy of the compound was an extrapolated
value.
[0374] Dielectric anisotropy (.DELTA..di-elect cons., determined at
25.degree. C.): when the sample was a compound, the compound could
be mixed with a suitable composition and then determined for the
dielectric anisotropy. In this case, the dielectric anisotropy of
the compound was an extrapolated value.
[0375] 1) For a composition with a positive dielectric anisotropy:
A sample was placed into a liquid crystal cell with a distance
(gap) of about 9 .mu.m between two glass substrates and a twist
angle of 80 degrees. The cell was applied with a voltage of 20 V to
determine the dielectric (.di-elect cons..sub..parallel.) in the
major axis direction of the liquid crystal molecule. Then, a
voltage of 0.5 V was applied to determine the dielectric (.di-elect
cons..sub..perp.) in the minor axis direction of the liquid crystal
molecule. The value of dielectric anisotropy was calculated
according to the equation .DELTA..di-elect cons.=.di-elect
cons..sub.81 -.di-elect cons..sub..perp..
[0376] 2) For a composition with a negative dielectric anisotropy:
A sample was placed into a liquid crystal cell, which was processed
into homeotropic alignment, and applied with a voltage of 0.5 v to
determine the dielectric (.di-elect cons..sub..parallel.). Then,
the sample was placed into a liquid crystal cell, which was
processed into homogeneous alignment, and applied with a voltage of
0.5 v to determine the dielectric (.di-elect cons..sub..perp.). The
value of dielectric anisotropy was calculated according to the
equation .DELTA..di-elect cons.=.di-elect
cons..sub..parallel.-.di-elect cons..sub..perp..
[0377] Threshold voltage (Vth, determined at 25.degree. C., V):
When the sample was a compound, the compound could be mixed with a
suitable composition and then measured for the threshold voltage.
In this case, the threshold voltage of the compound was an
extrapolated value. 1) For a composition with a positive dielectric
anisotropy: A sample was placed into an LCD device of a normally
white mode with a distance (gap) of (0.5/.DELTA.n) .mu.m between
two glass substrates and a twist angle of 80 degrees, in which
.DELTA.n was the value of refractive index anisotropy determined by
using the method above. A rectangular wave with a frequency of 32
Hz was applied to the device. Then, the voltage of rectangular wave
was increased, and the voltage value at which the transmittance of
light through the device reached 90% was determined.
[0378] 2) For a composition with a negative dielectric anisotropy:
A sample was placed into an LCD device of a normally black mode
with a distance (gap) of about 9 .mu.m between two glass
substrates, which was processed into homeotropic alignment. A
rectangular wave with a frequency of 32 Hz was applied to the
device. Then, the voltage of rectangular wave was increased, and
the voltage value at which the transmittance of light through the
device reached 10% was determined.
[0379] Voltage holding ratio (VHR, determined at 25.degree. C., %):
The TN device used for the determination had a polyimide alignment
film and a distance (cell gap) of 6 .mu.m between two glass
substrates. A sample was placed into the device, which was then
sealed with a UV-polymerizable adhesive. Then, the TN device was
charged by applying a pulse voltage (5V, 60 ms). The voltage decay
was determined by using a high-speed voltmeter at an interval of
16.7 ms, and the area A between the voltage curve and the
horizontal axis per unit cycle was calculated. The voltage holding
ratio was the percentage of the area A relative to the non-decayed
area B.
[0380] Helical pitch (determined at 20.degree. C., .mu.m): The
helical pitch was measured according to the Cano wedge cell method.
A sample was injected into a Cano wedge cell, and then the distance
(a, in .mu.m) between the disclination lines observed from the
wedge cell was measured. The helical pitch (p) is calculated
according to the equation p=2atan .theta., in which .theta. is the
angle between the two glass plates in the wedge cell.
[0381] Alternatively, the pitch length can be determined by
selective reflection (Handbook of Liquid Crystal, p 196, (issued in
2000, by Maruzen). For the selective reflection wavelength .lamda.,
the relationship <n>p/.lamda.=1 exists, where <n>
denotes the average refractive index, and can be calculated with
the equation
<n>={(n.sub..parallel..sup.2+n.sub..perp..sup.2)/2}.sup.1/2.
The selective reflection wavelength was determined with a
micro-spectrophotometer (trade name MSV-350, manufactured by Japan
Electronics Co., Ltd.). The pitch was obtained by dividing the
resulting reflection wavelength with the average refractive
index.
[0382] When the concentration of the chiral reagent is low, the
pitch of the cholesteric liquid crystal having a reflection
wavelength in a region of wavelength longer than that of visible
light is proportional to the reciprocal of the concentration.
Therefore, multiple points were measured in the pitch length of the
liquid crystal having a selective reflection wavelength in the
visible light region, and the pitch was calculated by using a
linear extrapolation method.
[0383] The proportion (percentage) of a component or a liquid
crystal compound is weight percentage (wt %) based on the total
weight of the liquid crystal compounds. The composition can be
prepared by mixing the components including liquid crystal
compounds after being weighed. Thus, the wt % of each component can
be easily calculated.
Example 12
[0384] A liquid crystal composition A was prepared by mixing the
liquid crystal compounds shown in figure below in the following
ratios.
[0385] The number of the compound of the present invention
corresponding to a general formula is recorded at the right side of
the structural formula
[0386] Liquid crystal composition A
##STR00105##
[0387] Phase transition temperature (.degree. C.) of the liquid
crystal composition A is N 63.1-64.2 I.
[0388] Then, a liquid crystal composition B containing the liquid
crystal composition A (94.2 wt %) and chiral reagents BN--H3 (2.9
wt %) and BN--H5 (2.9 wt %) represented by formulas below was
obtained.
[0389] Phase transition temperature (.degree. C.) of the liquid
crystal composition B is N* 51.5 BP 53.4 I.
[0390] In addition, BN--H3 and BN--H5 were obtained by
esterification of (R)-(+)-1,1'-bis(2-naphthol) and a corresponding
carboxylic acid, in the presence of dicyclohexyl carbodiimide
(DCC).
##STR00106##
Example 13
Preparation of Mixture of Monomer and Liquid Crystal
Composition
[0391] A liquid crystal composition B-1M was prepared by mixing
79.4 wt % of the liquid crystal composition B, 10.0 wt % of
n-dodecyl acrylate, 10.0 wt % of
1,4-bis(4-(6-(acryloxy)hexyloxy)benzoyloxy)-2-methylbenzene
(LCA-6), 0.6 wt % of 2,2'-dimethoxyphenylacetophenone as a photo
polymerization initiator, and was used as a mixture of the liquid
crystal composition and a monomer.
##STR00107##
Preparation of Polymer/Liquid Crystal Composite Material
[0392] The liquid crystal composition B-1M was held between a
non-aligned comb-like electrode substrate and the opposite glass
substrate (without an electrode) with a cell thickness of 10 .mu.m,
and then the resulting cell was heated until a non-liquid crystal
isotropic phase was formed at 57.0.degree. C. In this state, the
cell was irradiated with UV light of 365 nm at an intensity of 23
mWcm.sup.-2 for 1 min for polymerization.
[0393] The polymer/liquid crystal composite material B-1P thus
prepared could maintain an optically isotropic liquid crystal phase
even being cooled to room temperature.
Example 14
Preparation of Mixture of Monomer and Liquid Crystal
Composition
[0394] A liquid crystal composition B-2M was prepared by mixing
89.4 wt % of the liquid crystal composition B, 5.0 wt % of
n-dodecyl acrylate, 5.0 wt % of
1,4-bis(4-(6-(acryloxy)hexyloxy)benzoyloxy)-2-methylbenzene, and
0.6 wt % of 2,2'-dimethoxyphenylacetophenone as a photo
polymerization initiator, and was used as a mixture of the liquid
crystal composition and a monomer.
Preparation of Polymer/Liquid Crystal Composite Material
[0395] The liquid crystal composition B-2M was held between a
non-aligned comb-like electrode substrate and the opposite glass
substrate (without an electrode) with a cell thickness of 10 .mu.m,
and then the resulting cell was controlled to be 18.5.degree. C.,
so that a blue phase is exhibited. In this state, the cell was
irradiated with UV light of 365 nm at an intensity of 23 mWcm.sup.2
for 1 min for polymerization.
[0396] The polymer/liquid crystal composite material B-2P thus
prepared could maintain an optically isotropic liquid crystal phase
even being cooled to room temperature.
[0397] Furthermore, as shown in FIG. 1, the electrodes on the
comb-like electrode substrate were structured such that the
electrode 1 extending from the left side and the electrode 2
extending from the right side were alternatively arranged.
Therefore, when there is a potential difference between the
electrode 1 and the electrode 2, the comb-like electrode substrate
is provided with an electric field in two directions (upward and
downward), as shown in FIG. 1.
Example 15
[0398] A cell holding the polymer/liquid crystal composite material
B-1P obtained in Example 13 was arranged in the optical system of
FIG. 2 to measure the electro-optical properties. The light source
was the white light source with a polarizing microscope (ECLIPSE
LV100POL, manufactured by Nikon). The cell was arranged in the
optical system in a manner such that the incident light from the
light source irradiated on the cell was perpendicular to the
surface of the cell, and the line direction of the comb-like
electrode was at 45 degrees with respect to the polarizer and the
analyzer respectively. The relationship between the applied voltage
and the transmittance was investigated. If a rectangular wave of
65.0 V was applied, then the transmittance was up to 83%, and the
transmitted light intensity was saturated.
Example 16
[0399] A cell holding the polymer/liquid crystal composite material
B-2P obtained in Example 14 was arranged in the optical system of
FIG. 2 to measure the electro-optical properties. The light source
was the white light source with a polarizing microscope (ECLIPSE
LV100POL, manufactured by Nikon). The cell was arranged in the
optical system in a manner such that the incident light from the
light source irradiated on the cell was perpendicular to the
surface of the cell, and the line direction of the comb-like
electrode was at 45 degrees with respect to the polarizer and the
analyzer respectively. The relationship between the applied voltage
and the transmittance was investigated at room temperature. If a
rectangular wave of 65.0 V was applied, then the transmittance was
up to 79%, and the transmitted light intensity was saturated.
Example 17
[0400] A liquid crystal composition C was prepared by mixing the
liquid crystal compounds shown in figure below in the following
ratios.
[0401] The number of the compound of the present invention
corresponding to a general formula is recorded at the right side of
the structural formula.
##STR00108## ##STR00109##
[0402] Phase transition temperature (.degree. C.) of the liquid
crystal composition C is N 89.2-8 9.5 I.
[0403] Then, a liquid crystal composition D containing the liquid
crystal composition C (90.0 wt %) and chiral reagents BN--O5 (2.9
wt %) and BN--O6 (5.0 wt %) represented by formulas below was
obtained.
[0404] Phase transition temperature (.degree. C.) of the liquid
crystal composition D is 153.4 (N*+I).
[0405] In addition, BN--O5 and BN--O6 were obtained through
esterification of (R)-(+)-1,1'-bis(2-naphthol) and a corresponding
carboxylic acid, in the presence of dicyclohexyl carbodiimide
(DCC).
##STR00110##
Example 18
Preparation of Mixture of Monomer and Liquid Crystal
Composition
[0406] A liquid crystal composition D-1M was prepared by mixing
79.4 wt % of the liquid crystal composition D, 10.0 wt % of
n-dodecyl acrylate, 10.0 wt % of
1,4-bis(4-(6-(acryloxy)hexyloxy)benzoyloxy)-2-methylbenzene, and
0.6 wt % of 2,2'-dimethoxyphenylacetophenone as a photo
polymerization initiator, and was used as a mixture of the liquid
crystal composition and a monomer.
Preparation of Polymer/Liquid Crystal Composite Material
[0407] The liquid crystal composition D-1M was held between a
non-aligned comb-like electrode substrate and the opposite glass
substrate (without an electrode) with a cell thickness of 10 .mu.m,
and then the resulting cell was heated until a non-liquid crystal
isotropic phase was fowled at 63.0.degree. C. In this state, the
cell was irradiated with UV light of 365 nm at an intensity of 23
mWcm.sup.-2 for 1 min for polymerization.
[0408] The polymer/liquid crystal composite material D-1P thus
prepared could maintain an optically isotropic liquid crystal phase
even being cooled to room temperature.
Example 19
[0409] A cell holding the polymer/liquid crystal composite material
D-1P obtained in Example 18 was arranged in the optical system of
FIG. 2 to measure the electro-optical properties. The light source
was the white light source with a polarizing microscope (ECLIPSE
LV100POL, manufactured by Nikon). The cell was arranged in the
optical system in a manner such that the incident light from the
light source irradiated on the cell was perpendicular to the
surface of the cell, and the line direction of the comb-like
electrode was at 45 degrees with respect to the polarizer and the
analyzer respectively. The relationship between the applied voltage
and the transmittance was investigated at room temperature. If a
rectangular wave of 41.0 V was applied, then the transmittance was
up to 85%, and the transmitted light intensity was saturated.
Example 20
[0410] A liquid crystal composition E was prepared by mixing the
liquid crystal compounds shown in figure below in the following
ratios.
[0411] The number of the compound of the present invention
corresponding to a general formula is recorded at the right side of
the structural formula.
##STR00111## ##STR00112##
[0412] Phase transition temperature (.degree. C.) of the liquid
crystal composition E is N 89.2-89.5 I.
[0413] Then, a liquid crystal composition F containing the liquid
crystal composition E (93.0 wt %), and a chiral reagent BN--H3 (4.0
wt %) and BN-5 (3.0 wt %) was obtained.
[0414] Phase transition temperature (.degree. C.) of the liquid
crystal composition F is N*73.0 BP 76.0 I.
##STR00113##
Example 21
Preparation of Mixture of Monomer and Liquid Crystal
Composition
[0415] A liquid crystal composition F-1M was prepared by mixing
89.4 wt % of the liquid crystal composition F, 5.0 wt % of
n-dodecyl acrylate, 5.0 wt % of
1,4-bis(4-(6-(acryloxy)hexyloxy)benzoyloxy)-2-methylbenzene, and
0.6 wt % of 2,2'-dimethoxyphenylacetophenone as a photo
polymerization initiator, and was used as a mixture of the liquid
crystal composition and a monomer.
Preparation of Polymer/Liquid Crystal Composite Material
[0416] The liquid crystal composition F-1M was held between a
non-aligned comb-like electrode substrate and the opposite glass
substrate (without an electrode) with a cell thickness of 10 um,
and then the resulting cell was heated until a blue phase was
formed at 35.0.degree. C. In this state, the cell was irradiated
with UV light of 365 nm at an intensity of 23 mWcm.sup.-2 for 1 min
for polymerization.
[0417] The polymer/liquid crystal composite material F-1P thus
prepared could maintain an optically isotropic liquid crystal phase
even being cooled to room temperature.
Example 22
[0418] A cell holding the polymer/liquid crystal composite material
F-1P obtained in Example 21 was arranged in the optical system of
FIG. 2 to measure the electro-optical properties. The light source
was the white light source with a polarizing microscope (ECLIPSE
LV100POL, manufactured by Nikon). The cell was arranged in the
optical system in a manner such that the incident light from the
light source irradiated on the cell was perpendicular to the
surface of the cell, and the line direction of the comb-like
electrode was at 45 degrees with respect to the polarizer and the
analyzer respectively. The relationship between the applied voltage
and the transmittance was investigated at room temperature. If a
rectangular wave of 55.0 V was applied, then the transmittance was
up to 86%, and the transmitted light intensity was saturated.
Example 23
[0419] A liquid crystal composition G was prepared by mixing the
liquid crystal compounds shown in figure below in the following
ratios.
[0420] The number of the compound of the present invention
corresponding to a general formula is recorded at the right side of
the structural formula.
##STR00114## ##STR00115##
[0421] Phase transition temperature (.degree. C.) of the liquid
crystal composition G is N 87.1-87.8 I.
[0422] Then, a liquid crystal composition H containing the liquid
crystal composition G (91.5 wt %) and chiral reagents BN--H3 (4.75
wt %) and BN-5 (3.75 wt %) was obtained.
[0423] Phase transition temperature (.degree. C.) of the liquid
crystal composition H is N.sup.*60.1 BP.
##STR00116##
Example 24
Preparation of Mixture of Monomer and Liquid Crystal
Composition
[0424] A liquid crystal composition H-1M was prepared by mixing
89.4 wt % of the liquid crystal composition H, 5.0 wt % of
n-dodecyl acrylate, 5.0 wt % of
1,4-bis(4-(6-(acryloxy)hexyloxy)benzoyloxy)-2-methylbenzene, and
0.6 wt % of 2,2'-dimethoxyphenylacetophenone as a photo
polymerization initiator, and was used as a mixture of the liquid
crystal composition and a monomer.
Preparation of Polymer/Liquid Crystal Composite Material
[0425] The liquid crystal composition H-1M was held between a
non-aligned comb-like electrode substrate and the opposite glass
substrate (without electrode) with a cell thickness of 10 .mu.m,
and then the resulting cell was heated until a blue phase was
formed at 34.0.degree. C. In this state, the cell was irradiated
with UV light of 365 nm at an intensity of 23 mWcm.sup.-2 for 1 min
for polymerization.
[0426] The polymer/liquid crystal composite material H-1P thus
prepared could maintain an optically isotropic liquid crystal phase
even being cooled to room temperature.
Example 25
[0427] A cell holding the polymer/liquid crystal composite material
H-1P obtained in Example 24 was arranged in the optical system of
FIG. 2 to measure the electro-optical properties. The light source
was the white light source with a polarizing microscope (ECLIPSE
LV100POL, manufactured by Nikon). The cell was arranged in the
optical system in a manner such that the incident light from the
light source irradiated on the cell was perpendicular to the
surface of the cell, and the line direction of the comb-like
electrode was at 45 degrees with respect to the polarizer and the
analyzer respectively. The relationship between the applied voltage
and the transmittance was investigated at room temperature. If a
rectangular wave of 75.0 V was applied, then the transmittance was
up to 85%, and the transmitted light intensity was saturated. The
response time when a saturation voltage is applied at room
temperature is increased to be 1.1 ms and is decreased to be 0.4
ms, and is a high-speed response time.
Example 26
[0428] A liquid crystal composition I was prepared by mixing the
liquid crystal compounds shown in figure below in the following
ratios.
[0429] The number of the compound of the present invention
corresponding to a general formula is recorded at the right side of
the structural formula.
##STR00117## ##STR00118## ##STR00119##
[0430] Phase transition temperature (.degree. C.) of the liquid
crystal composition I is N 87.3-88.9 I.
[0431] Then, a liquid crystal composition J containing the liquid
crystal composition I (93.7 wt %) and the chiral reagent BN--H3
(6.3 wt %) was obtained.
[0432] Phase transition temperature (.degree. C.) of the liquid
crystal composition J is N*74.8 BP.
##STR00120##
Example 27
Preparation of Mixture of Monomer and Liquid Crystal
Composition
[0433] A liquid crystal composition J-1M was prepared by mixing
89.0 wt % of the liquid crystal composition J, 5.4 wt % of
n-dodecyl acrylate, 5.0 wt % of
1,4-bis(4-(6-(acryloxy)hexyloxy)benzoyloxy)-2-methylbenzene, and
0.6 wt % of 2,2'-dimethoxyphenylacetophenone as a photo
polymerization initiator, and was used as a mixture of the liquid
crystal composition and a monomer.
Preparation of Polymer/Liquid Crystal Composite Material
[0434] The liquid crystal composition J-1M was held between a
non-aligned comb-like electrode substrate and the opposite glass
substrate (without an electrode) with a cell thickness of 10 .mu.m,
and then the resulting cell was heated until a blue phase was
formed at 41.0.degree. C. In this state, the cell was irradiated
with UV light of 365 nm at an intensity of 23 mWcm.sup.-2 for 1 min
for polymerization.
[0435] The polymer/liquid crystal composite material J-1P thus
prepared could maintain an optically isotropic liquid crystal phase
even being cooled to room temperature.
Example 28
[0436] A cell holding the polymer/liquid crystal composite material
J-1P obtained in Example 27 was arranged in the optical system of
FIG. 2 to measure the electro-optical properties. The light source
was the white light source with a polarizing microscope (ECLIPSE
LV100POL, manufactured by Nikon). The cell was arranged in the
optical system in a manner such that the incident light from the
light source irradiated on the cell was perpendicular to the
surface of the cell, and the line direction of the comb-like
electrode was at 45 degrees with respect to the polarizer and the
analyzer respectively. The relationship between the applied voltage
and the transmittance was investigated at room temperature. If a
rectangular wave of 65 V was applied, then the transmittance was up
to 87%, and the transmitted light intensity was saturated. The cell
maintains an optical isotropy without crystallization at 0.degree.
C. for 1 week.
APPLICABILITY IN INDUSTRY
[0437] The present invention is applicable, for example, in the
field of optical device, such as display device using a liquid
crystal medium.
* * * * *